The most important sea engagement of World War One - the Battle of Jutland - is being commemorated 90 years on.
HMS Edinburgh sailed to the site of the battle
The Imperial War Museum is holding an exhibition on HMS Belfast, while wreaths have been laid at the scene of the confrontation, off Denmark's coast.
One of the last survivors, 109-year-old Henry Allingham, from Eastbourne, East Sussex, was at the exhibition's launch.
Some 8,648 British and German sailors lost their lives in one day's fighting on 31 May into 1 June 1916.
A hologram of Mr Allingham, who is Britain's oldest man, is also displayed onboard the naval museum moored on the River Thames between Tower Bridge and London Bridge.
"Ghosts of Jutland" combines oral history, artefacts, documents and film to convey the lives and experiences of the sailors who fought in the battle.
Meanwhile, the British destroyer HMS Edinburgh and the German frigate FGS Karlsruhe met at the site of the battle for a service of commemoration.
Mr Allingham will be 110 years old next week
And the UK government announced that wrecks of the 14 British ships that were sunk during the battle will be given new protection.
Veterans' minister Tom Watson announced the wrecks will become "protected places" under the Protection of Military Remains Act, meaning people can "look but not touch".
Mr Watson said he was "delighted" to be offering protection against "disturbance and desecration" to the wrecks.
The Battle of Jutland lasted for about 16 hours, from 31 May into 1 June 1916. Both sides claimed victory.
The British lost more men and more vessels, but the Germans never again seriously contested control of the seas with their battleships, instead turning to unrestricted submarine warfare.