AN UNDERWATER archaeology project to map the wreckage of seven top secret Second World War ‘Valentine’ tanks will be launched in Purbeck tomorrow.

In the months leading up to D-Day, the largest amphibious landing in history, waters off the Dorset coast became testing grounds for the operation to come.

On April 18, 1944, Prime Minister Winston Churchill, King George VI and General Dwight D. Eisenhower - Supreme Commander of the Allied Forces - met at Fort Henry, near Studland, to watch a rehearsal of the assault.

As Operation Smash unfolded, a number of the Valentines, which had been equipped with propellers and canvas skirts to make them amphibious, were deployed.

Sadly, as a portent of things to come, seven of these Valentines sank during the operation - with the loss of seven lives.

The Isle of Purbeck Sub Aqua Club (IPSAC) will announce, at Purbeck Sports Centre on Friday evening, a two-year project to record, survey and research the history of these seven tanks, two of which remain at the bottom of Poole Bay to this day. Club chairman Chris Dunkerley said: “The tanks are a favourite dive for many of us and we have decided to collect as much information about them as we can. “

In 2019 the club will mark the 75th anniversary of Operation Smash.

Chris said: “We plan to create an exhibition about them to commemorate the event in which, sadly, seven soldiers lost their lives.

“Project Valentine 75 is our attempt to keep the history of the event alive. Over the years the tanks have started to disintegrate and unfortunately five were blown up for safety in the 1980s by the Royal Navy. Project Valentine 75 will provide a lasting record of the tanks and the information collected will enable underwater archaeologists to monitor their condition in the future.”

During the actual D-Day landings, almost all of the 112 amphibious tanks launched offshore as part of the American attack on Omaha Beach, were lost.

However, the overwhelming majority of crewmen were rescued by other landing craft.

The underwater Valentine 75 Project starts on April 4, with a poppy wreath laid to commemorate the soldiers who died.