“He was a passionate diver and he loved everything about it.

“He will be sorely missed by all of us.”

A spokesman for Spencair said last night that staff at the company were still trying to let the news of their boss’s death “sink in”.

The spokesman added that a decision on how to pay tribute to Mr Spencer will be made when workers return from their bank holiday break today.

Mr Spencer was part of a team filming the wreck of the Britannic, the British World War I hospital ship that sank off the island in 1916 after hitting a mine.

The Britannic Foundation, headed by British businessman Simon Mills, wants to preserve the ship.

Greek Ministry of Merchant Marine spokeswoman, Aspa Papadopoulou, said Mr Spencer was found “unconscious with decompression sickness symptoms”.

“Everything was done to save his life,” she said.

“A fully-equipped military Super Puma helicopter was rushed in to take him to the best possible hospital in Athens and even in flight every possible method of artificial respiration was tried to resuscitate him.

“The helicopter landed at the military airport of Katechaki, on the outskirts of Athens, after which he was rushed to the Athens Naval Hospital because there is a decompression chamber there.”

The possibility that faulty equipment caused his death has not yet been ruled out with the coroner’s report expected later today.