TRAINEE navigators went to sea on HMS Portland for their specialist training.

HMS Portland played host to the students, who had to navigate complex passage plans close to navigational risks while travelling at high speed.

The students were stopped from using key navigational equipment, forcing them to rely on old fashioned sextants and stop watches.

Over the course of two weeks, HMS Portland sailed 3,000 nautical miles around the UK, visiting the Western Isles of Scotland, Northern Ireland, Wales, Southern England and the Channel Islands.

One of the students on the course, Lieutenant Patrick Kelley, said: "It was the most challenging, yet rewarding, course I have undertaken during my time in the Royal Navy."

Of the seven who started the course, five finished it successfully and have now gone on to join the ranks of the Royal Navy’s elite navigators.

During the training HMS Portland went to anchor in Scapa Flow in the Orkneys where the ship’s company paid respect to 833 men and boys who lost their lives onboard HMS Royal Oak sunk by torpedoes from a German submarine October 14, 1939.

Today the Royal Oak is a recognised war grave and is protected from the intrusion of recreational divers who do not have authority to dive around the wreck.

Each year on October 14th a team of Royal Navy divers descend to the wreck and fly the white ensign above the overturned hull of the Royal Oak in memory of those who served on board but did not survive the attack by the U-47.

HMS Portland commanding officer, Captain Simon Asquith, said: "It’s really important that we continue to pay our respects to those who have given their lives in the service of their country.

"It’s also a very potent reminder of what submarines are capable of and why we must continue to hone the effectiveness of our current day anti submarines warfare tactics."

HMS Portland is one of the youngest Type 23 frigates.

Portland's namesake warship came to the island last week and welcomed visitors on board while she anchored in the port for a short visit.