A hospital ship sunk off the coast of Shepway during the First World War has finally been recognised as an official war grave.

The sinking of HMHS Anglia and the Chatham-based cruisers HMS Aboukir, HMS Cressy and HMS Hogue claimed the lives of nearly 1,700 sailors, nurses and soldiers.

The law granting them legal protection from diving expeditions and recognising them for the first time as official military graves comes into effect today.

HMHS Anglia was lost on November 17, 1915 after striking a mine just outside Folkestone Harbour as she returned to Britain with nearly 400 injured soldiers from the battlefields.

In addition to the wounded soldiers, a team of doctors and nurses was also on board.

At least 160 people died when the ship sank after hitting a German mine a few miles east of Folkestone at 12.30pm.

The designation follows a campaign to have the ships listed and protected by maritime historians.

One of the campaigners, Christopher Conn, from Folkestone, said he was pleased the ship had now been given the protection.

He previously said he wanted the protection to stop “sport divers” from taking souvenirs from the ship.

An expedition to recover one of Anglia’s two anchors was carried out in July 2008 by divers from the Folkestone Yacht and Motor Club Scuba-diving section, the British Sub Aqua Club and Shorncliffe Professional Association of Diving Instructors centre.

Mr Conn said: “There was a proposal mentioned to raise Anglia’s remaining anchor.

"Now, with the Protection on the Military Remains Act 1986, the HMHS Anglia is an official war grave, this should not happen, the ship and her 167 dead can be allowed to rest in peace.”

Mark Dunkley, a marine archeologist with Historic England, said: “The wrecks are now legally protected and recognised as military maritime graves.

“In protecting these historic wreck sites, the Ministry of Defence has recognised the significance of the ships as part of our national story, recognised the cultural importance of the First World War at sea, and honoured the memory of those lost in the defence of our shores.

“Historic England is pleased to have supported the Ministry of Defence.”

Three men from Sandgate were among the 1,459 sailors killed when German submarine U9 fired eight torpedoes and sunk the three Royal Navy cruisers, Aboukir, Cressy and Hogue just seven weeks in to the conflict on September 22, 1914.

Petty Officer Stoker William Epps, 47, who was married to Margaret Epps, who lived in the High Street, and Chief Stoker Albert Fagg, both of the Cressy, lost their lives.

Able Seaman William Bruce Drayner was 30 and was on the Hogue when she sank.

It was one of the worst disasters for the Royal Navy in the war, and they became known as the Live Bait Squadron afterwards.

Members of the 7th Cruiser Squadron, based at Chatham, the ships were tasked with patrolling the Dover Straits between the Dutch and English coasts.

Horrendous weather forced their destroyer escort to return home but the three elderly cruisers carried on unprotected, standing out due to their smoking funnels from the steam engines.

When the weather cleared, they were spotted by the U-boat commander Otto Weddigen, who launched his attack.

A few days after the sinking, press reports began circulating in the Folkestone newspapers about casualties, including Lord Radnor’s 15-year-old son, who was on the Hogue.

He survived and was picked up and taken to Holland.

Gillingham and Rainham MP Rehman Chishti lobbied Parliament in November 2014 for the three ships to be protected, launching a petition.

HMHS Anglia, HMS Aboukir, HMS Cressy and HMS Hogue are among 13 wartime vessels to be added to the list under the Protection of Military Remains Act 1986.

There are 79 wrecks of ships and submarines on the list – including five German submarines and Second World War Allied cargo vessels.

Under the law it is illegal for divers to damage, move, remove or unearth the remains.

It is also against the law to “enter any hatch or other opening in any of the remains” or if a person causes or permits anyone to carry out those acts.