It will be 100 years on 9 July since HMS Vanguard exploded and sank off Orkney with the loss of 843 lives.
Safeguarded under the Protection of Military Remains Act 1986, diving is not permitted at the site except under licence from the MoD.
A team of specialist divers aboard Orkney dive boat MV Huskyan were given special permission by the MoD to explore the wreck.
Emily Turton, of MV Huskyan, said: “The main wreck is complicated with an extensive debris field. Surprisingly, given the nature of her loss, both the bow and stern are intact despite large pieces of wreckage having being thrown hundreds of metres away.
“HMS Vanguard was legally salvaged during the second half of the 20th century and much evidence ... remains.
“It is accepted that the likely cause of the disaster was an accidental magazine explosion.
“Witness accounts on the night of her loss describe a large explosion immediately behind the bridge. We can reveal that our initial survey result supports this.”
The survey team is made up of a team of specialists who explored HMS Hampshire in June 2016.
A full sonar survey of the wreck site has now been completed with the help of Kevin Heath of Sula Diving. This will provide an insight into the ship’s history after a century spent underwater.
A report will also be compiled for the MoD, Historic Environment Scotland, Orkney Marine Services and other interested organisations.
Ms Turton added: “The purpose of this survey is to tell the story of HMS Vanguard at 100 years underwater. We also hope to offer a sensitive contribution to the centenary commemoration in July this year.”
Scapa Flow is popular with divers because of the number of wrecks hidden beneath its waters.
It was the main anchorage of the Royal Navy and has many relics in its waters from British naval history.
In June 1919, the interned German navy scuttled most of its high seas fleet there to prevent ships from falling into Allied hands. Eight of the vessels remain at the site.