The 75th anniversary of one of the worst losses in British naval history will marked held in Orkney tomorrow.
The Royal Oak was torpedoed by a German U-boat in 1939.
Most of the 1,200 crew were asleep below deck, and more than 800 died, including more than 100 boy sailors.
On the day of the 75th anniversary of the tragedy, a wreath will be laid over the wreck site in Scapa Flow.
None of the remaining survivors, of which there are believed to be just three, will be attending.
The Sandown-class mine hunter HMS Bangor has been on a six-day visit to Kirkwall as part of a series of events marking the anniversary.
The wreath will be laid from its deck by Rear Admiral John Clink.
A special commemoration service at the Royal Oak Garden of Remembrance in Scapa will take place before the wreath-laying, conducted by the Rev David Dawson.
Yesterday a service was also held in St Magnus Cathedral at Kirkwall, and there will be a talk by the Royal Navy Presentation Team today at Orkney Theatre.
HMS Royal Oak sank in Scapa Flow on October 14, 1939, with the loss of 834 lives, after being hit by torpedoes from German U-Boat U-47.
The raid made an immediate celebrity and war hero out of the U-boat commander, Günther Prien, who became the first German submarine officer to be awarded the Knight’s Cross of the Iron Cross.
Before the sinking of Royal Oak, the Navy had considered the base at Scapa Flow impregnable to submarine attack, and U-47’s raid demonstrated that the German navy was capable of bringing the war to British home waters.
The shock resulted in rapid changes to dockland security and the construction of the Churchill Barriers around Scapa Flow.
Launched in 1914 and in service in 1916, the Revenge Class battleship saw service in the First World War, including the Battle of Jutland.
The torpedo strikes which claimed the ship and so many lives were delivered barely a month into World War II.
But over the years the wreck also became an environmental hazard leaking oil.
By 2010, about 1,600 tonnes of fuel oil had been removed, and the wreck was declared to be no longer actively releasing oil into Scapa Flow.
Navy divers from Northern Diving Group have also made their annual visit to the site as part of the anniversary.
The wreck is an official maritime war grave.
As well as replacing the white ensign which “flies” at the stern of the ship, the divers have undertaken the routine yearly survey of the wreck.