HMS Vanguard was one of three St Vincent-class dreadnought battleships built for the Royal Navy in the first decade of the 20th century.

Aside from participating in the Battle of Jutland in May 1916 and the inconclusive action of 19 August several months later, her service during World War I mostly consisted of routine patrols and training in the North Sea.

It was designated as a controlled site under the Protection of Military Remains Act 1986, and diving on the wreck is generally forbidden.

The turbines were rated at 24,500 shaft horsepower (18,300 kW) and intended to give the ship a maximum speed of 21 knots (39 km/h; 24 mph).

Vanguard carried enough coal and fuel oil to give her a range of 6,900 nautical miles (12,800 km; 7,900 mi) at a cruising speed of 10 knots (19 km/h; 12 mph).

[2] The St Vincent-class ships were protected by a waterline armoured belt 8–10 inches (203–254 mm) thick that extended between the end barbettes.

Their decks ranged in thickness between 0.75 to 3 inches (19 to 76 mm) with the thickest portions protecting the steering gear in the stern.

[Note 2] Vanguard was commissioned on 1 March 1910, under the command of Captain John Eustace,[11] and assigned to the 1st Division of the Home Fleet.

Arriving in Portland on 27 July, she was ordered to proceed with the rest of the Home Fleet to Scapa Flow two days later[12] to forestall a possible surprise attack by the Imperial German Navy.

[18] Submarine scares such as this caused the fleet to be briefly (22 October to 3 November) based at Lough Swilly, Ireland, while the defences at Scapa were strengthened.

On the evening of 22 November, the Grand Fleet conducted a fruitless sweep in the southern half of the North Sea; Vanguard stood with the main body in support of Vice-Admiral David Beatty's 1st Battlecruiser Squadron.

[21] On the evening of 23 January, the bulk of the Grand Fleet sailed in support of Beatty's battlecruisers,[22] but they were too far away to participate in the ensuing Battle of Dogger Bank the following day.

Throughout the rest of the month, the Grand Fleet was performing numerous training exercises before making another sweep into the North Sea on 13–15 October.

On the night of 25 March, Vanguard and the rest of the fleet sailed from Scapa Flow to support Beatty's battlecruisers and other light forces raiding the German Zeppelin base at Tondern.

[12] On 21 April, the Grand Fleet conducted a demonstration off Horns Reef to distract the Germans while the Russian Navy re-laid its defensive minefields in the Baltic Sea.

The fleet returned to Scapa Flow on 24 April and refuelled before proceeding south in response to intelligence reports that the Germans were about to launch a raid on Lowestoft.

[29] During the Battle of Jutland on 31 May, Beatty's battlecruisers managed to bait Scheer and Hipper into a pursuit as they fell back upon the main body of the Grand Fleet.

[30] Shortly after deploying from column into line ahead, her crew recorded that shells from the High Seas Fleet were falling nearby.

During the first stage of the general engagement, the ship fired 42 rounds from her main guns at the crippled light cruiser SMS Wiesbaden beginning at 18:32,[Note 4] claiming several hits.

This was the last time that the ship fired her guns during the battle, as the poor visibility hindered Jellicoe's ability to close with the Germans before Scheer was able to disengage under the cover of darkness.

A total of 843 men were lost, including two Australian stokers from the light cruiser HMAS Sydney who were serving time in the battleship's brig.

It showed no signs of a blast from 'A' magazine, which reinforced the visual evidence suggesting that the explosion took place in the central part of the ship.

The inquiry found that some of the cordite on board, which had been temporarily offloaded in December 1916 and catalogued at that time, was past its stated safe life.

The bow and stern areas are almost intact as has been revealed by an extensive survey, carried out by a team of volunteer specialist divers and authorised by the Ministry of Defence in 2016.