Veterans and serving military personnel are about to take on one of the most difficult endurance races in the world - the Talisker Whiskey Great Atlantic Challenge.
Twenty-eight teams in total are taking on the 3,000-mile row, facing 40-foot waves, hunger and extreme tiredness as they travel from their start line at La Gomera in the Canary Islands to Antigua in the Caribbean.
Of those 28 teams, five are either made up of veterans or serving personnel from the UK Armed Forces.
One team with a military background is Row4Victory - a tri-service team of four.
They are raising money for military charity, 'Soldier On!', and as part of their commemorations to mark the centenary year of World War One, The Royal British Legion.
Former Royal Engineer and member of the Row4Victory team, Duncan Roy, talked about how military skills will come in useful with the more challenging mental aspects of the race: "It’s obviously a physical challenge but it is massively a mental challenge.
"When it’s 2 o’ clock in the morning and you’re missing home and you’re cold wet and hungry, I think the guys are going to lean on the skills they learnt in the military…
"Past experiences of how to dig deep and how to carry on, you know, cheerfulness in the face of adversity.”
Every person taking part has their own reason to do so.
Former Royal Marine Special Boat Service, Tim Crockett, is one of the five solo racers. His reason for taking part is about raising awareness of PTSD in memory of a former Royal Marine he'd served with.
He told Forces News about how they had reconnected on social media.
“It was about six weeks later that I heard that he’d taken his own life – he’d been suffering from post-traumatic stress pretty badly.
“I had that itch that I just couldn’t scratch and I felt that I needed to do more.”
He told Forces News that he’d come across the Talisker Whisky Atlantic Challenge through another friend he’d served with, and saw that it was a “great charitable platform.
“While it is a race, everyone here has one or more charities that they’re supporting and rowing for, and obviously my charities are linked to veterans’ mental health.”
'Grandads of the Atlantic', are as their name implies, Grandads with a combined age of 123 years.
Both Neil Young and Peter Ketley are former Paratroopers who served in the Falklands War - they hope to become the oldest people ever to row across an ocean.
Men Of Oar are also made up of former and serving personnel, who in total have completed four tours of Afghanistan. They are aiming to raise £250,000 for military charity Combat Stress and Bowel Cancer UK.
Robin Drysdale from 21 Signal Regiment is the boat's captain and also a bowel cancer survivor. He says he wants to do the race to raise awareness about the disease and show it can be beaten.
Here he is giving us a tour round their boat:
The race's military connection extends beyond the UK Armed Forces.
The owner of the race is a former Danish Army officer, meanwhile, there is also an American team called 'Fight Oar Die'. They are the first all-American veteran team to take the challenge on.
Today saw the competitors put in their very final preparations - checking their equipment, rations and seeing how the race will begin.
However, strong winds along the island saw today's practice cut short.
On Wednesday, they will begin their challenge - taking on the best the Atlantic has to throw at them.
To follow the team's journey across the Atlantic, click here.