Sailors have been put to the test on the Royal Navy's "premier" navigation course aboard HMS Severn.
The Portsmouth-based warship took navigators hoping to serve aboard aircraft carriers HMS Queen Elizabeth and Prince of Wales, or pass on their skills to a new generation of sailors, through challenging training in the narrow waterways around Scotland, Northern Ireland and the Orkney Islands.
The course trains navigators to "the highest degree the Royal Navy can" by "pushing mental capacity and situational awareness", the Navy said.
"Training the very highest standards of navigation for the Royal Navy’s premier navigation course isn’t easy, but it gives the service a battle-winning edge," said Commander Phil Harper, Commanding Officer of HMS Severn, who has previously completed the course and passed on advice to the students during their training.
"This has been a stunning professional highlight for the ship and for me personally."
Students on the Specialist Navigator Course spend eight weeks in the classroom and two weeks at sea with HMS Severn.
Routinely deprived of technology like GPS, gyro and radar, the students were tasked with guiding patrol ship HMS Severn and a mock task group through dangerous waters.
During the first week of the course, the seas were turbulent with wind over the deck reaching 78 knots.
In these conditions, the student navigators had to plan and execute highly complex navigation for a ghost task group consisting of Severn and up to three imaginary consorts.
In the Orkney Islands, Severn paid her respects to HMS Royal Oak, the battleship torpedoed at anchor in Scapa Flow by a German submarine in 1939, killing 835 people.
She also travelled around the isles of Mull, Bute, Arran and Skye.
After the specialist navigators course was complete, Severn took new students aboard for the general Fleet Navigating Officers’ course.
The offshore patrol vessel was re-commissioned into the Royal Navy in July, nearly three years after she was decommissioned.
Picture: Royal Navy.