Royal Marines

Marines: UK vs US – Bootnecks versus leathernecks

One requires its members to be Semper fidelis ("Always faithful"), and the other to go Per Mare, Per Terram ("By Sea, By Land".)

These are the mottos of the US Marine Corps (USMC) and the UK's Corps of Royal Marines, otherwise known as leathernecks and Bootnecks. 

Being marines, both organisations have a lot of overlap in that they are essentially amphibious infantry, although the ways in which they fulfil this role also differ considerably. So how exactly do they compare?

Very simply, the Royal Marines is a group of elite amphibious commandos, while the USMC is an immense organisation that is essentially an entire military force in and of itself.

Getting into the Royal Marines requires persisting through to the end of the tough basic commando training course, and then becoming part of a relatively small force of light, amphibious infantry.

Becoming a US Marine, by contrast, requires one to push through a much quicker basic training regime before getting stuck into life in the Corps, then topping up skills periodically while navigating a career through a giant seaborne army.

Those, at any rate, are the basic differences.

What follows is a more in-depth comparison of these two formidable amphibious forces.

Members of 45 Commando training in Slovenian mountains
Royal Marines from 45 Commando training in Slovenia (Picture: MOD).

Round one: histories

As it happens, going head to head with the Royal Marines fits in perfectly with the early history of the USMC, which began its life by fighting the British.

The original US marines were Continental Marines, formed in 1775 at the start of the American War of Independence. They fought alongside George Washington's Continental Army and took part in their first amphibious assault in 1776 – on the British port at Nassau, in the Bahamas.

They were disbanded after the war, although were re-established in 1798, this time within an officially created US Marine Corps. They then went on to take part in the 1798-1800 (undeclared) Quasi-War against France, a naval conflict on US East Coast and in the Caribbean.

The First Barbary War was also an important early campaign for the US Marine Corps. It lasted from 1801 to 1805 and was launched to protect American merchant ships from pirates from the Barbary states in North Africa.

The Marine Corps have their own hymn, the first two lines of which refer to specific actions in the "Halls of Montezuma" and at the "shores of Tripoli".

The latter refers to an 1805 battle fought during the First Barbary War at the port town of Derna in Libya, after eight US marines and about 500 foreign mercenaries trekked across the desert to besiege it. The valour of one marine officer, Presley O'Bannon, is said to have won him the admiration of a local prince named Hamet Karamanli, who then presented him with a Mameluke sword.

It is this sword that has been said to have been the inspiration for marine officers carrying swords after 1825, although this has been disputed by the Marine Corps Historical Program's newsletter 'Fortitudine'. The newsletter also refers to (and disputes) one story that had O'Bannon passing the sword to a comrade through whom it eventually ended up at the US Naval Academy Museum.

Whatever the exact details of the story, it seems the legend of O'Bannon and the great victory at Derna are both strong enough to have become associated with marine officers' dress swords, as well as to get a specific mention in the Marines' Hymn.

Marines 1 Marine Division at Richard Nixon Presidential Library and Museum in 2013
Marines from 1st Marine Division at the Richard Nixon Presidential Library and Museum in 2013 – notice the red stripes on their trousers (Picture: DVIDS).

Likewise, the other great action mentioned in the hymn, which took place at the “Halls of Montezuma", is similarly legendary. It is a reference to the Battle of Chapultepec, a major engagement towards the end of the Mexican-American War. This battle is noteworthy for the sheer level of sacrifice on the part of the Marine Corps, with their official website saying it led to the deaths of 90% of the Marine Corps officers and NCOs who took part. It also states that the tradition of Marine Corps officers and NCOs wearing red stripes on their trousers is derived from this battle, with the red in the stripes representing the blood that was shed.

This last point has also been disputed since the wearing of red stripes predated the 1847 battle. Once again though, as with O'Bannon and Derna, the association of the red stripes with Chapultepec seems to have more to do with the legendary status of the battle than anything else. It was clearly another impressive episode in the long history of the Corps, of which there have been many.

Two more of particular relevance here are the 1815 Battle of New Orleans, in which British and American Marines faced each other while embedded in larger forces, and the role played by the Corps in the Second World War.

Starting with the Battle of New Orleans, this may not be specifically mentioned in the Marines' Hymn, but it does have its own (rather amusing) song. Performed initially by Jimmy Driftwood, it was covered later by other artists including Jimmy Horton and Johnny Cash.

The battle took place at the end of the War of 1812 and resulted from the British trying to invade the town of New Orleans and the surrounding area. Under the leadership of the then Brevet Major General and future President Andrew Jackson, American forces had gathered outside New Orleans to resist the invasion.

In the song, Jackson is referred to as a colonel and it describes how "the British kept a'comin" after the Americans repeatedly fired at them until eventually they "began to runnin'" down the Mississippi River and out to sea. While not exactly a precise military history of the event, it does capture the lop-sidedness of the fight: the British sustained about 2,000 casualties as compared to about 60 for the American side.

US Marines raising the flag at Iwo Jima
The US Marines raise the American flag after their victory at Iwo Jima (Picture: Alamy CWA078).

Also of particular note is World War 2, where the Marines played a vital role in the Pacific War against Japan, sustaining over 80,000 casualties in the process and earning 82 Medals of Honor. The conflict with Japan led to what is quite possibly the most iconic photograph in US Marine Corps history, and perhaps also US Second World War history more generally: the Marines raising the flag after their victory at Iwo Jima.

The Marines then went on to fight the Japanese on Okinawa, where they prevailed at the end of June 1945, roughly a month-and-a-half before the dropping of the first atomic bomb.

Now, of course, Japan and the US are allies, and the US Marines have a presence on Okinawa today, something that will be discussed below.  

The Second World War was also highly significant in the history of Britain's Royal Marines. This was the period when they went from being Royal Marines to becoming Royal Marine Commandos, since the role of elite coastal raiders, taken up by members of the Royal Marines and some in the Army during the war, was retained by the Marines in the years afterward.

As it happens, even if the word commando had not yet come into general British military use, the Royal Marines ended up performing a kind of commando role during World War 1 as well. In April 1918, 1,700 Royal Marines raided the port of Bruges-Zeebrugge in Belgium in a mission to block access to the sea by German U-boats.

Before that, the Royal Marines' history stretched back officially to 1664 when King Charles II gave an order for the formation of foot soldiers specifically for the purpose of service aboard Royal Navy ships. This was not the first time these 'sea-service' soldiers had been organised (and later disbanded) for naval operations, though it was the first time such soldiers were referred to as 'marines'.

In 1755, British marines became a permanent force, in 1802, they officially became a royal one, when Admiral St Vincent secured a 'Royal' title from the king.

Then, as now, the Marines performed a variety of roles, being both ship and shore-based, acting as ship fighters during ship-to-ship combat, as well as being extra muscle for tasks at sea, and attacking and defending coastal positions and naval bases. These last roles meant their importance increased considerably as the British Empire expanded during the 18th and 19th Centuries.

In all then, both the USMC and the Royal Marines have rich and varied histories with much to be proud of.

Round one is thus a draw.

Royal Marines amphibious landing North Africa WW2
Royal Marines conduct an amphibious landing in North Africa during the Second World War (Picture: National Archives and Records Administration).

Round two: today's forces

Today, the UK has about 7,000 Regular (or full-time) Royal Marines within the Royal Navy, with approximately 1,000 Royal Marine Reservists. Precise figures for 1 July 2021 released by the MOD in response to a Freedom of Information Request indicate that there are 6,892 full-time Royal Marines with an additional 1,080 reservists – although 56 of these reservists are in the Full-Time Reserve Service, which is included in the figure of 6,892 full-time marines.

By contrast, the projected Fiscal Year 2020 figure for the number of active duty (i.e. full-time) US Marine Corps personnel was 186,200.

To put that into perspective, the MOD's quarterly personnel statistics for 1 July 2021 lists the number of personnel serving in all branches of the British Armed Forces – including Regular, Reserve, Gurkha and other personnel – as 198,800. In other words, there are almost as many active-duty US Marines as there are people in the whole of the British military.

Additionally, the MOD's Navy website lists its personnel as being more than 30,000, while the quarterly personnel figure for 1 July 2021 is more precise: 40,640 – a figure inclusive of Regular, Reserve and other personnel, as well as all Royal Marines, Regular and Reserves.

Royal Marine Commandos standing in formation aboard a ship
Royal Marines taking part in a remembrance service aboard a Landing Craft Utility or LCU (Picture: MOD).

The USMC 2020 figure for the number of marine reservists is 38,500, so even this portion of the Marine Corps is broadly comparable in scale to the whole of the Royal Navy, at least in terms of the number of personnel in it.

This also means the number of USMC reserves outnumber Royal Marine Reserves by more than 60 to one. (Note that not all of these are like UK Royal Marine Reserves – some are indeed ground troops, though others serve in aviation and logistics reserve units).

Put simply, the United States Marine Corps dwarfs the Corps of Royal Marines, which means that both are very different organisations in terms of their presence, global remits and how they perform them.

However, in terms of raw stomping power, the USMC obviously far exceeds the Royal Marines, given the huge difference in the number of personnel.

Round two therefore goes to the leathernecks.

US Marines and sailors aboard USS Iwo Jima in 2011
US Marines and sailors aboard the USS Iwo Jima in 2011 (Picture: DVIDS).

Round three: training and basic formations

While the Royal Marines may be a relatively small force, they are far from lacking in training. Indeed, their basic training course is 32 weeks long and is the longest infantry training in NATO.

As well as being expected to develop and maintain high levels of fitness, recruits at the CTCRM (Commando Training Centre Royal Marines) in Lympstone, Devon are given a broad array of exercises and tasks. There are multiple field exercises, instruction in weapons handling (this includes specialist weapons), tactics and leadership, map reading, marksmanship, close-quarter combat, and lessons on deploying from assault boats and helicopters.

They are also taught very rudimentary tasks. Veteran Cassidy Little went through the Commando training course and had this to say:

"They literally teach you from the very basics - how to iron something, how to wash, how to make your bed, how to use a knife and fork, how to brush your teeth. If you can’t be trusted to maintain your own teeth, how can you be trusted to manage a weapons system?"

The whole course culminates in four tests: an endurance course consisting of multiple tunnels, pools, bogs, woods, streams and a four-mile run back to camp followed by a shooting test; a nine-mile speed march to be completed in 90 minutes with equipment and rifle; an aerial assault course that must also be completed while carrying rifle and equipment, this time in 13 minutes; and a 30-mile march with equipment and rifle to be done within eight hours.

Little wonder that the average drop-out rate is around 40%, though it can also get considerably higher, closer to 75%. Cassidy Little said that when he went through the Commando course only 13 of the 54 who originally started the training made it all the way to the end.

Ghana 2013
Those who become Royal Marines form part of an elite group of amphibious infantry who are trained to fight anywhere in the world- this Royal Marine is doing jungle training in Ghana in 2013 (Picture: MOD).

For those who pass through training, there are a myriad of different roles they could end up performing within the Royal Marines. The most conventional path leads to the force’s two main fighting commandos, 40 and 45 Commandos.

Using 40 Commando as an example, that would mean serving within a battalion-sized unit of around 500 personnel that is broken down into six companies: two Close Combat Companies – Alpha and Charlie Companies, each with company HQs and three platoon-sized Close Combat Troops of rifle sections and a manoeuvre section; two Stand Off Companies – Bravo and Delta Companies, each with either tracked or wheeled transport and heavy machine gun and anti-tank troops, as well as their own close combat troops; a Logistic Company; and a Command Company, with its own reconnaissance, signals, mortar, anti-tank and machine-gun troops.

Within each troop, marines have traditionally worked within sections of eight, though that is beginning to change.

Royal Marines recruits doing the mud run as part of their basic training and selection
The Mud Run, part of Royal Marines training at the Commando Training Centre in Lympstone (Picture: MOD).

For those training instead to become US Marines, they will first attend a 13-week boot camp at either Parris Island in South Carolina or San Diego in California.

At these training locations, marine recruits must also focus on physical fitness, aiming to improve it throughout as they learn about the Marine Corps, first aid, martial arts, bayonet fighting and marksmanship with the M-16 assault rifle. The US Marines put particular emphasis on marksmanship training, devoting the better part of two weeks of the three-month course to it.

Speaking to Business Insider about this aspect of marine boot camp training, Primary Marksmanship Instructor Sergeant Jonathan Gilbert said:

“First off is the fundamentals. They have to understand how to aim. They have to understand exactly how to breathe when they’re taking a shot. They have to understand exactly how to squeeze the trigger and how to have follow through and recovery with the rifle.”

There are a range of other skills honed as well during training, such as marching, swimming, abseiling, climbing obstacles and fighting with pugil sticks, which are designed to simulate fighting with a bayonet mounted on the end of a rifle. Recruits are also trained in the use of gas masks and exposed to tear gas, as well as having drill instructors barking orders at them throughout the three-month course.

US marine recruits practising marksmanship at Parris Island boot camp
US marine recruits practising marksmanship at the Parris Island boot camp (Picture: DVIDS).

Unlike UK marine recruits, those going through boot camp within the US system only have one major obstacle to overcome towards the end of their training. The bad news is that ‘the Crucible’ lasts for 54 hours and allows recruits very little food and sleep - yet they are still expected to apply everything they have learnt. They perform a total of 48 miles of marching and engage in combat simulations such as evacuating wounded comrades from dangerous areas, doing assault courses and martial arts challenges, and they must also succeed at navigation courses, patrols and other challenges. Teamwork is stressed throughout.

According to, attrition rates for boot camp are usually between 12 and 16%, and for the majority who pass through it successfully, just like the Royal Marines, there are a large number of specialist roles on the other side. In US Marine parlance, these are known as MOSs, or Marine Occupational Specialties.

One key aspect of the US Marine boot camp experience is that it links the training to future service in the marines by placing recruits within training units that mimic those in the real world. That essentially means training in (and perhaps later serving in) fireteams of four, rifle squads or sections of 13, platoons made up of three rifle squads, rifle companies made up three platoons (and, in real life, a command element as well as a weapons platoon with machine guns, mortars and anti-tank rocket launchers.)

A marine battalion is in turn made up of three rifle companies, a supporting weapons company and a headquarters and service company.

From there, the usual pattern is for marine infantry battalions to be organised into regiments, and then regiments organised into a division. The US Marines do use brigades as well, something that will be explored below.

There is an important caveat here: in 2018, then Commandant of the Marine Corps, General Robert B Neller announced his intention in the near future to switch the Marines from having rifle squads of 13 marines to having rifle squads of 12. The plan revolves around the smaller squads having fire teams of three individuals instead of four, and a squad commander supported by a deputy commander and a technical specialist. This is in large part a function of changes weaponry, something that will be explored below.

In all though, no matter what the exact structure of their units, being vastly larger and more complex than the Royal Marines means that the USMC have many opportunities for their marines to take on all kinds of different roles. Some of these will involve them become elite special operations marines.

However, due to the fact that the far-more comprehensive basic training of the Royal Marines makes them a kind of special operations force by default, round three goes to the Bootnecks.

US marine recruits crawling through mud as they do the Crucible, the final part of their basic training
US marine recruits doing the Crucible at Parris Island in 2015 (Picture: DVIDS).

Round four: organisation

While the Royal Marines are one of five component fighting arms of the Royal Navy (the others being the Fleet Air Arm and Royal Fleet Auxiliary and Surface and Submarine Fleets), the USMC is its own sub-branch of the Navy.

To be precise, the Department of the Navy is divided into the US Navy and the Marines Corps. The 2020 Fiscal Year figure for the number of active-duty personnel in the US Navy is 340,500. This means the USMC’s 186,000 (active-duty) personnel make up about a third of the roughly 526,500 (active-duty) personnel serving in the whole of the Department of the Navy.

Yet the Marine Corps is still considered a co-equal branch of the Department of the Navy and this relatively greater prominence is reflected at the very top too, within the political arena.

In the UK, the Chiefs of Staff Committee, which advises the government on military matters, consists of five members, two of whom are the Chief of the Defence Staff (the professional head of the British Armed Forces) and the Vice-Chief of the Defence Staff. The other three are the heads of three services: the First Sea Lord and Chief of the Naval Staff; the Chief of the General Staff (the head of the British Army) and Chief of the Air Staff (the head of the RAF.)

Lieutenant General Robert Magowan Commandant General Royal Marines
Lieutenant General Robert Magowan, Commandant General Royal Marines since April 2021, nearest the camera (Picture: MOD).

In other words, the Royal Marines fall under the Royal Navy. Indeed, the Commandant General Royal Marines Robert Magowan, the professional head of the service, is placed within Navy Command Headquarters as Commander UK Amphibious Forces, while full command of the Royal Marines lies with the Royal Navy’s Fleet Commander.

In the US, by contrast, the President and other members of the Executive Branch of the US Government have the Joint Chiefs of Staff to advise them on military matters. As well as Chairman and Vice Chairman of the Joint Chiefs, this includes six military branch heads: that of the National Guard, the chief of space operations and the heads of other four services - the Army, US Air Force, the US Navy and the Marines Corps. In other words, the head of the Marine Corps, General David H Berger (who replaced General Robert Neller in 2019), is also a member of the Joint Chiefs.

However, even if the USMC is much larger and more self-sufficient than its British equivalent, it is still not entirely independent. For example, it relies on the US Navy for transport to a theatre of operations. Likewise, the US Navy relies on the Marine Corps for tasks such as taking and holding naval bases during campaigns in wartime.

US Navy ships that support 31st Marine Expeditionary Unit
US Navy support for 31st Marine Expeditionary Unit, a US Marine Air-Ground Task Force which will be described below (Picture: DVIDS).

In terms of how the units within the two services are distributed, to understand the Royal Marines, one must again return to the commandos, the battalion-sized units of about 500 men whose lineage, as noted, can be traced back to the Second World War. (Commando can in fact refer to the unit, or those who serve in them).

There are six commandos in today’s Corps of Royal Marines, as well as the Commando Logistic Regiment (which gives logistical support), reserves, engineers, the Royal Marines Band Service and the Commando Training Centre Royal Marines (CTCRM), which provides its training and keeps up its standards.

The six commandos, their bases and the roles they perform are as follows:


Role and location

30 Commando

Based at 3 Commando Brigade HQ in Stonehouse Barracks, Plymouth. Aids the HQ of 3 Commando Brigade (the main RM field formation)

40 Commando

Along with 45 Commando, a fighting commando close in function to an Army infantry battalion. Based at Norton Manor Camp in Taunton, Somerset.

42 Commando

Specialist marine assault unit based at 3 Commando Brigade HQ in Bickleigh Barracks, Plymouth.

43 Commando

Fleet protection unit based at HMNB Clyde in Scotland.

45 Commando

A fighting commando close in function to an Army battalion, based at RM Condor in Arbroath, Scotland.

47 Commando

A raiding group based at 3 Commando Brigade HQ in Stonehouse Barracks, Plymouth.

General David H Berger, Commandant of the United States Marine Corps and one of the Joint Chiefs (Picture: DVIDS).
General David H Berger, Commandant of the United States Marine Corps and one of the Joint Chiefs (Picture: DVIDS).

The essential fighting core of the USMC, meanwhile, is its 24 active-duty infantry battalions, as well as the reserve battalions supporting them. (This is due to drop to 21 active-duty battalions over the course of the decade up to 2030 as part of a slimming-down plan for the Marine Corps known as Force Design 2030).

USMC reserve infantry battalions come under the umbrella of the United States Marine Corps Reserve, which has the largest number of assigned personnel of any command within the USMC, while its regular infantry battalions are part of the Marine Corps Operating Forces.

As well as its infantry battalions and their supporting elements (more below), USMC Operating Forces also include the Marine Security Guard, which protect US embassies around the world, and Marine Corps Security Forces, which guard US naval bases and ships (i.e. like 43 Commando does in the UK.) There are even Marine Corps guards and a US Marine helicopter squadron at the White House.

Meanwhile, Headquarters Marines Corps is responsible for the organisation, internal discipline, administration, training and other affairs required to keep the USMC running.

There is also the Supporting Establishment, which deals with recruiting, recruiting depots, maintains bases and air stations and handles logistics and the US Marine Band. It also contains Combat Development Command, which looks ahead to possible future warfare scenarios and helps the Marines prepare for them.

While these vast and varied remits make the US Marine Corps highly complex, its operating forces can at least be more easily understood by breaking them down geographically.

Like the Royal Marines in the UK, they have a large presence within the US, and this presence then extends beyond the US’s East and West Coasts. Each side of the US contains what are known as MEFs (Marine Expeditionary Forces), which will be explained in more detail below. For now, the MEFs can be thought of as large groupings of marine ground forces along with supporting elements that sit under two larger command structures on either side of the US.

These umbrella command organisations, including their MEFs, are arrayed as follows:

Marine Force Pacific (MARFORPAC)

Marine Forces Command (COMMARFORCOM)

This force is based in both the Pacific and on the West Coast of the US, in Marine Corps Installations West. In short, III MEF is based in Okinawa, Japan, while I MEF is based on the American West Coast.


Fleet Marine Force, Pacific – which is essentially a US version of what the UK is doing with its Littoral Response Groups (LRGs) and Future Commando Force (FCF) – also comes under the umbrella of this force.


Marine Forces Command is based on the East Coast of the US and controls Marine Corps Installations East.


Marine Forces Command’s main building block is II MEF, and additional supporting units.


Mirroring Marine Force Pacific, Marine Forces Command controls its own littoral, forward-deployed force: Fleet Marine Force, Atlantic. 

Note that as well as being situated on East and West Coasts of the US, and in Japan, and part of respective parts of the Fleet Marine Force, the Marine Corps regularly contributes personnel to various combatant commands around the world.

These are essentially command structures based around an ongoing mission or function that perform their roles using personnel from two or more branches of the US military. There are 11 of these in total, four function based (Cyber Command, Special Operations Command, Strategic Command and Transportation Command) and seven geographic or area based: Africa Command, Central Command, European Command, Northern Command, Southern Command, Space Command, and Indo-Pacific Command. MARFORPAC is, for instance, the USMC’s service component command of Indo-Pacific Command.

President Trump boarding Marine One in Japan in 2017
President Trump boarding Marine One in Japan in 2017 (Picture: DVIDS).

In all then, both US and UK marine forces are situated in a variety of places as they continue to fulfil current roles, while also preparing for future ones based on the littoral response concept of units forward deployed at sea, ready for action within a given world region.

Since both forces seem to be performing their existing roles and preparing for future ones equally well, round four is a tie.

Round five: equipment

Being by nature amphibious soldiers, marines of any nation require both land and sea-based vehicles and other supporting kit to make them an effective fighting force.

It is impossible to cover all of that here, but an overview of some of the main vehicles and weaponry will give a sense of how the Royal Marines and USMC go about fulfilling their roles.

In terms of small arms, both forces are similarly equipped.

The main weapon of the Royal Marines is currently, like soldiers in the British Army, the L85-A2. This has a 30-round clip and can fire its 5.56mm rounds on semi or fully automatic, or in small bursts. It is sighted for an effective firing range of up to 400 metres. The A3 variant is also in use, and in fact the Royal Marines use a mixture of different models of SA80.

Some marines have also begun using the Colt Canada C8, which, like the L-85, also fires 5.56mm rounds to a maximum effective range of 400 metres, though is very different in appearance, looking more like an American M4 carbine.

Royal Marine 45 Commando training raid Slovenian mountains
A Royal Marine from 45 Commando training in the Slovenian mountains in 2021 – he wields an L85 assault rifle (Picture: MOD).

As it happens, the M4, along with the M16, has in fact been the traditional standard arm of the US Marines, and American forces more generally. However, in recent years the Heckler and Koch M27 has become the standard weapon for Marines, since it has proved to be more capable than the M4.

The M27 does not fire in bursts, only in semi and fully automatic modes, yet it has a high rate of fire (up to 700 rounds a minute in full auto) and a long range: 600 metres for a point target (i.e. a single person), and 800 metres for an area target (i.e. successfully hitting one or more people among a small group of the enemy.)

The capabilities of the M27 IAR (Individual Automatic Rifle) have contributed to the decision in 2018 of the head of the Marine Corps for rifle squads to go from 13 personnel down to 12.

Part of this change is based around technology, with the new squads gaining a technical specialist who controls drones. However, it is also about weapons.

The traditional pattern of one squad leader and three four-man fireteams has been based around each fireteam having its own SAW (Squad Automatic Weapon) – in other words a light machine gun (the M249 – known to the British as the Minimi) that has provided more rapid firepower when required.

The new squad arrangement is based on the idea that personnel with assault rifles that are more rapid firing, accurate and longer ranged than their previous M4s (or even M16s) can do as much damage as those equipped with M4s and M249s. This is not to say that the Marine Corps expects its troops to put down as many rounds with their magazine-fed M27s as they otherwise would have with both M4s and belt-fed M249s. Rather, the idea is that more-accurate less-rapid assault-rifle fire can do as much damage as less-accurate, if more-rapid, light-machine-gun fire.

3rd Battalion 8th Marine Regiment fire the M27 2017
A US Marine from 3rd Battalion, 8th Marine Regiment firing an M27 assault rifle in 2017 (Picture: DVIDS)

Beyond the main assault rifles and carbines, US Marines use an array of small arms weaponry that is broadly similar to the weapons used  by the Royal Marines. Both use 9mm side arms; both use many of the same machine guns (the M249/Minimi while still in use, .50-calibre machine guns, the FN-MAG General Purpose Machine Gun, which the British call the L7A2 and the Americans the M240G); both use sniper rifles, a number of which are higher calibre 7.62mm, though the US Marines have a marksmanship version of the M27 called the M38, as well as .50-calibre M82 sniper rifle, which is also in use by the British Army, who refer to it as the L135A3.

Both also use 40mm grenade launchers (in fact, grenadiers play an important role in the new US Marine squad layout), 60 and 81mm mortars, rocket launchers and artillery. Though, in fact, artillery support for the Royal Marines is provided by the British Army, and Force Design 2030 changes mean many artillery units in the USMC are being converted to HIMARS (more below.)

The main difference between the USMC and the Royal Marines in terms of equipment lies in the vehicles they use, and this once again is a result of the huge differences in scale between the two forces.

Royal Marine Viking armoured amphibious vehicle conducting trianing in Norway in 2021
A Viking conducting training in Norway in 2021 (Picture: MOD).

Leaving aside logistical vehicles and those for regular functional tasks like the Wolf Land Rover, the Royal Marines have a handful of vehicles that support them in getting onto and remaining ashore: the Viking, which provides armoured protection as it carries Royal Marines to shore and across lakes and rivers; the BV206, which is similar and provides additional tracked transport; the four-wheeled Jackal and a small number of six-wheel Coyotes, which provide protection from mines and enable Marines to conduct reconnaissance; and a small number of beach recovery vehicles known as Hippos, which can haul boats and vehicles up and down beaches.

US Marines, meanwhile, have a much larger pool of ground vehicles with which to support their infantry. These include armoured vehicles like the AAV – Amphibious Assault Vehicle – which fulfils the same role for the USMC’s as the Viking – as well as the LAV-25 for reconnaissance and HIMARS (High Mobility Artillery Rocket System – a truck-based rocket launcher) for fire support. Until very recently, the USMC even had M1 Abrams tanks, though has reported as of April 2021 these have been transferred to the US Army.

The USMC also has a range support vehicles like the Medium Tactical Vehicle Replacement family of vehicles, the Humvee and the M1163 Prime Mover (a kind of jeep) as well as others including a range of engineering vehicles.

US Marines with HIMAR rocket launcher
US Marine reservists from 2nd Battalion, 14th Marines (4th Marine Division) loading up an M142 HIMAR rocket launcher in 2017 (Picture: DVIDS).

The Royal Marines do have their own range of watercraft, such as the Landing Craft Utility Mk 10, Off-shore Raiding Craft (ORC) and Inflatable Raiding Craft, though US Marines have a number of boats provided by the Navy (as the Royal Navy also supports the Royal Marines, to be completely accurate) that perform identical functions.

Where the two forces really diverge is in their aircraft.

Put simply, the Royal Marines do not have any, whereas the USMC have a vast array of helicopters and planes with which to shuttle their personnel over the waves below and onto shore. They also use aircraft to support them while they are there.

Not that British military planners have neglected air support for the Royal Marines. There is an entire portion of the Royal Navy’s Fleet Air Arm dedicated to Royal Marine air transportation and support -- the Commando Helicopter Force. And in fact, once they become operational, the Royal Navy’s F-35B Lightnings could theoretically be directed to support Royal Marine operations, just as the British military (and all modern militaries) naturally work to support comrades in different branches.

Yet the US Marine Corps does not just need support from the US Navy’s or USAF’s F-35s every so often -- it has its very own F-35s. It also has its own F-18 fighter jets and Harriers (many of which, admittedly, have been replaced by F-35s), Hercules support aircraft and a range of different helicopters such as the Huey and the Viper attack helicopter.

But perhaps the most iconic of all the US Marines’ current aircraft is the V-22 Osprey. Designed with the distinctive tiltrotor, this aircraft can, like the Harrier, perform vertical take off and landing, as well as fly horizontally like a propellor-driven aircraft, reaching a top speed of over 300 mph. When it lands and takes off, it functions like a helicopter with two rotor blades (i.e. like a British Chinook), and when it flies it rotates these forwards and uses them as giant propellers. Ospreys are capable of carrying over 30 troops into battle this way.

So overall, the Royal Marines have good kit, as well as wider support from their comrades in the Navy (and, if needed, the RAF and Army.) Though it is of course difficult for them to compete with their US counterparts when it comes to having their own Ospreys, fighter jets and tanks (at least until the latter were removed from the USMC inventory.) 

Round five therefore goes to the leathernecks.

MV-22 US Marine OSpreys in flight
US Marine Ospreys in flight (Picture: DVIDS).

Round six: 3 Commando Brigade versus 31 Marine Expeditionary Unit

US Marine aircraft are not merely a result of their marine corps being a much larger force with far more equipment. Rather, aircraft are integrated deeply into Marine Corps structure, forming one side of a triangle that makes up larger units within the USMC. The other two sides of that triangle are made up of logistics and Marine infantry.

As the training and basic formations section of this article pointed out, the standard marine is trained to become part of a series of progressively larger units, starting with a fireteam and ending in a division. Marine infantry divisions do not necessarily have exactly the same number of units and can therefore vary slightly in size, though they are usually about 20,000 personnel strong.

There are three active-duty infantry divisions within the USMC: 1st Marine Division, 2nd Marine Division and 3rd Marine Division.

Traditionally and historically, an army division was meant to be a kind of self-functioning, large-scale military unit consisting of multiple infantry battalions and any support elements they might require to fight on a battlefield of the time. For instance, British Army infantry divisions of the First World War were at first made up of about 18,000 men -- 12,000 in a dozen infantry battalions, and then support personnel, mostly those in artillery units assigned throughout the division.

The First World War is also instructive in another way. During that period, both British and American infantry divisions were organised into armies known as the BEF and the AEF: the British Expeditionary Force and the American Expeditionary Force. The ‘expeditionary’ part referred to their being expected and able to form up as needed and then go and fight overseas.

Many of the Operating Forces in today’s US Marine Corps are organised around a similar principle, but one applied to 21st Century warfare.

Thus, 1st, 2nd and 3rd Marine Divisions make up only one of three vital parts of the main US Marine forces. To be an effective expeditionary force on today’s amphibious battlefields, US Marines who are infantry also have US Marine comrades who are aviation and logistical specialists. All three are organised into Marine Expeditionary Forces, or MEFs (pronounced “mefs”.)

These are I MEF, II MEF and III MEF (or one mef, two mef, and three mef, if one were to write the names as they would be pronounced.)

As pointed out above, I MEF makes up much of the US Marine Forces that are based on the West Coast of the US and it contains not only 1st Marine Division, but also 3rd Marine Air Wing (its aviation element) and 1st Marines Logistics Group (its logistics element.) These three are in fact literally referred to as the MEF’s ground combat element, aviation combat element and logistics combat element. There is also a command element (which has various supporting units) as well as a handful of other units that act as headquarters for smaller expeditionary units, something that will be explained just below.

This structure is replicated in II MEF - which has 2nd Marine Division, 2nd Marine Aircraft Wing and 2nd Marine Logistics Group making up its ground, aviation and logistics combat elements, respectively – as well as in III MEF, which has 3rd Marine Division, 1st Marine Aircraft Wing and 3rd Marine Logistics Group.

The USMC is also able to use its vast pool of reservists to form 4th Marine Division, 4th Marine Aircraft Wing and 4th Marine Logistics Group, effectively providing the Corps with one whole backup ground, aviation and logistics combat element each.

The deeply integrated nature of the three main combat elements is reflected not only in their inclusion within MEFs, but also in the concept of the Marine Air-Ground Task Force, or MAGTF.

Amphibious Assault Vehicle 7s shown driving up a beach - these vehicles support US Marines
Amphibious Assault Vehicle 7s, which help support the ground combat elements of US Marine MAGTFs (Picture: DVIDS).

Like the name suggests, Marine Air-Ground Task Forces contain both air and ground elements, these being the ground and logistics combat elements and the aviation combat elements contained in the MEFs. This is how US Marine Operating Forces are generally deployed – namely, together and always in support of one another. This must be one very good example of where the team-work ethos drummed into recruits in their Marine boot camps displays itself.

Because they have all three constituent parts, MEFs are themselves a form of MAGTF, and an entire MEF could theoretically be deployed during wartime. Though more commonly, smaller MAGTFs are formed from subunits within the MEFs.

The smallest and most common of these is the Marine Expeditionary Unit, or MEU (pronounced “mew”.)

At a minimum, an MEU consists of a single infantry battalion from a MEF’s marine infantry division, a single squadron from a MEF’s marine aircraft wing, and a combat logistics battalion from a MEF’s marine logistics group. In practice, if the MEU is formed from its parent MEF*, this means taking an infantry battalion from an available pool of anywhere between roughly half-a-dozen and 16 battalions (depending on how many there are in each marine infantry division inside a given MEF), and aircraft wings and combat logistic battalions coming from similar pools of available units.

(*MEUs can be formed from units within their parent MEF, or from those in other MEFs).  

All this takes a MEU’s size to about 2,000 personnel (which includes sailors as well as marines, since the Navy is also involved the deployment of MAGTFs.) However, this could swell in times of conflict to about double that number. MEFs also have a number of other supporting units like landing support, transportation support, aviation logistics squadrons and medical, supply, engineer and other support units that could prove useful and necessary to an MEU during a conflict. Hence the potential increase in a MEU’s size during a conflict.

Each MEF also has an expeditionary brigade within it that has no permanently assigned subunits but can act as a headquarters when an MEB (Marine Expeditionary Brigade) is formed. This is an intermediate-sized MAGTF which is about three times as large as an MEU, whereas a MEF is about three times as large as an MEB.

In total, there are seven MEUs within the US Marine Corps, three in I MEF, three in II MEF and one in III MEF. The latter of these, 31st MEU, is the only permanently deployed Marine Expeditionary Unit in the Marine Corps. The other three are based within the US and are sent out as needed. For instance, II MEF routinely sends out its three MEUs – 22nd, 24th and 26th Marine Expeditionary Units – from the East Coast of the US on a rotating basis to serve in Europe (i.e. as part of European Command.)

The story with 31st MEU and III MEF, however, is different. Both are based in Okinawa, Japan, where 31st MEU is permanently on the ready. Its composition is interesting in that it in turn has its own permanently assigned unit: its logistics combat element, Combat Logistics Battalion 31 (though technically, CLB 31 is assigned to 3rd Marine Logistics Group in III MEF.)

However, because units within MEUs can change (this flexibility is of course the whole point), 31 MEUs aviation and ground combat elements are less permanent. Example units are Marine Medium Tiltrotor Squadron 262 (VMM-262) as the aviation element, which comes from 31 MEU's parent body, III MEF. Meanwhile, an example ground combat element is 2nd Battalion, 4th Marines regiment, which comes from I MEF.

262 Tiltrotor Squadron in Japan in 2019
Marine Medium Tiltrotor Squadron 262 (VMM-262) in Japan in 2019 (Picture: DVIDS).

Starting with the ground combat component, 2nd Battalion, 4th Marines has over 1,000 personnel arrayed in those fireteams, squads, platoons and companies discussed earlier. These troops will have an array of small arms including assault rifles, machine guns, grenade launchers and support weaponry like the Javelin rocket launcher.

Meanwhile, the “Flying Tigers” in VMM-262 can deliver their comrades in the ground combat element via multiple Ospreys. These can be used to transport troops directly, or as an airborne platform from which personnel can parachute down to a given objective. There are also helicopters like the Huey UH-1Y “Yankee” available to provide additional air support since MEU aviation combat elements are typically reinforced with additional types of aircraft.

Speaking on the US Marine Corps’ video channel on YouTube, Huey UH-1Y pilot Captain Marianne Sparklin explains:

“The Huey is one of the most versatile aircraft that the Marine Corps has to offer. It’s a utility platform, it can be used for a variety of mission sets, ranging from delivering mail to taking marines to season objectives, to providing close air support to the friendly units on the deck.”

That support can come in the form of sharpshooters aboard the Huey, or a .50-calibre machine gun or M134 Minigun (designated as the GAU-17/A.)

US Marine sniper taking aim from a helicopter
A US Marine sniper on the lookout from a helicopter (Picture: DVIDS).

As if that is not enough air support, 31st MEU also has additional help that can be supplied by F-35B Lightnings.

In terms of logistics, Combat Logistics Battalion 31 provides engineering support, maintenance, supplies, bomb disposal expertise, landing support, communications, motor transport, ammunition supplies, post, medical services, a headquarters and military police (though Force Design 2030 aims to remove these from the USMC.)

It is also worth mentioning that there is special operations support for any MEU as well. US special operations is a complex and obscure area, for obvious reasons. However, most available information indicates this support comes from those in Marine Force Recon (or Force Reconnaissance), Marine Raiders, Marine Raider support battalions and, quite likely, a combination of all these.

As for the Royal Marines in 3 Commando Brigade (their main field formation), every one of them is in a sense essentially a special operations soldier anyway. The elite-level training inevitably leads to marines who must and do remain fit and elite throughout their careers. As Lieutenant Jones puts it on the Royal Navy’s own page dedicated to the Marines:

“Life in the Royal Marines can be tough, but I wouldn’t have it any other way. You need to really push yourself, mentally and physically. It’s more than just a job. It’s a lifestyle.”

45 Commando training part of 3 Commando Brigade Norway with GPMG, heavy machine gun, grenade machine gun
3 Commando Brigade training in Norway with GPMGs, heavy machine guns, grenade machine guns (Picture: MOD).

As for the Royal Marines in 3 Commando Brigade (their main field formation), every one of them is in a sense essentially a special operations soldier anyway. The elite-level training inevitably leads to marines who must and do remain fit and elite throughout their careers. As Lieutenant Jones puts it on the Royal Navy’s own page dedicated to the Marines:

“Life in the Royal Marines can be tough, but I wouldn’t have it any other way. You need to really push yourself, mentally and physically. It’s more than just a job. It’s a lifestyle.”

The name of the game for the Royal Marines is to combine their various specialisms in the most effective ways along with any wider support elements from elsewhere in the Royal Navy and British military more generally.

At the core of 3 Commando Brigade, that means using the Royal Marines’ two main battle formations – 40 and 45 Commandos.

When deployed, these two commandos can use the best of the weaponry outlined above to take on an enemy. These include not only standard weapons like the L-85 assault rifle, but also machine guns, sniper rifles, grenade launchers, mortars and rocket launchers.

Specialist assault of enemy positions would likely be provided by 42 Commando, and raiding by 47 Commando, all of them assisted by information gathering and cyber warfare provided by 30 Commando. Meanwhile, 43 Commando would provide protection to any ships from the Royal Navy used to help transport the brigade into action.

Just as 31st MEU have their logistic combat element, the Royal Marines in 3 Commando Brigade have the Commando Logistics Regiment to supply and support them. There is also transport assistance from 539 Raiding Squadron.

In terms of air support, the Royal Marines can not bring in their own aircraft but Merlin and Wildcat helicopters from the Royal Navy’s Commando Helicopter Force can and do provide air transport and attack when the Marines require it. As and when the Fleet Air Arm’s F-35Bs become operational (this is scheduled for 2023), they too could theoretically be tasked with supporting any action involving 3 Commando Brigade.

Royal Marine Commando with RAF Chinook hovering in the background
The RAF also assist the Royal Marines – visible here is a member of 40 Commando taking part in Exercise Green Dragon 2021 with an RAF Chinook in the background (Picture: MOD).

The British Army also have a number of units that feed into 3 Commando Brigade, providing artillery, engineering and additional logistical support.

In all then, 31st MEU and 3 Commando Brigade achieve much the same level of force projection, just in different ways. For the Royal Marines, it is a case of bringing together a small group of elite individuals with complementary expertise as well as the necessary wider supporting elements.

For the United States Marines, while they too utilise support from their navy, they draw on their own vast pool of assets and personnel to assemble and support well-equipped Marine Expeditionary Units whenever they are required to deploy (permanently in the case of 31 MEU.)

Thus, the Bootnecks and the leathernecks tie again.

3 Commando Brigade

31 Marine Expeditionary Unit

Personnel: 3,500

HQ: Includes elements from the RAF, Army and Navy

Frontline units: 40, 42 and 45 Commandos

Army support elements: 24 Commando Regiment, Royal Engineers; 29 Commando Regiment, Royal Artillery; 383 Commando Petroleum Troop, Commando Logistic Regiment

Royal Marine support elements: Personnel from 43 Commando (Fleet Protection Group), 47 Commando (Raiding Group), 30 Commando (Information Exploitation Group), Commando Logistic Regiment

Royal Marine transport elements: 539 Raiding Squadron (including the Royal Marine Armoured Support Group)

Additional transport from Royal Navy ships and helicopters from the Commando Helicopter Force, part of the Royal Navy’s Fleet Air Arm.


Personnel: 2,200 (including US Navy sailors), and this can swell considerably in wartime

Command element (company sized)

Ground Combat Element: 2nd Battalion, 4th Marines Regiment (functioning as the BLT – Battalion Landing Team – and including amphibious vehicles, artillery and other supporting elements)

Aviation Combat Element: Marine Medium Tiltrotor Squadron 262 (VMM-262) flying MV-22B Ospreys – these are reinforced with other aircraft like F-35 jets (replacing the AV-8B Harrier across the USMC’s MEUs), Hercules planes, and helicopters

Logistics Combat Element: Combat Logistics Regiment 31

Additional transport for MEUs comes in the form of US Navy amphibious assault ships, warships and submarines to transport, escort and protect those within the MEU.

As pointed out at the beginning of this article, comparing the Royal Marines with the USMC could not be a straight comparision since they are such different forces, but this is an exploration of the two.

Thanks to the Royal Marines Historical Society for some assistance with this article.

Cover image: merged pictures of Royal Marines shown marching in 2014 (Picture: MOD) and American Marines marching in Washington, DC in 2014 (Picture: DVIDS).

Tug of War Royal Marines and US Marines in Bahrain in 2019
A friendly tug of war between Royal Marines (left and back) and members of the US Marine Corps (right and front) in Bahrain in 2019 (Picture: DVIDS).

Join Our Newsletter


RAF C-17 becomes biggest aircraft to land on tiny remote island

Ukraine war: What we know about the destroyed Nova Kakhovka dam

Inside the world of an RAF fighter pilot policing Nato's Baltic skies