"My uncle worked as a stoker in the ship's engine room so was probably one of the first to go."
HMS Pathfinder was patrolling waters off southern Scotland when it was hit. The crew below decks had no opportunity to escape and went down with the ship.
"You hear a lot about the soldiers that died," said Mr Stern, "but not much about the sailors and I think it is important they get a mention.
"It is doubly unusually to hear about a Jewish sailor so it is important for our family to remember him."
Mr Stern found out that his uncle was the first Jewish sailor to be killed during WW1 after looking into his family history. He said: "I never met my uncle but his story was one I grew up with.
"After the war, in 1922, Caxton Publishing Company printed a limited edition of the British Jewry Book of Honour.
"It lists a total of 503 officers and others in the Royal Navy and Royal Naval Division; 32 are shown as having been killed in action and the dates of their deaths are given. William Stern's is the earliest recorded."
Dave Lock, a BSAC national diving committee member and group leader for diving and coaching, will lead the group of divers. He said it would be a "poignant and sombre occasion… showing respect to the wreck and to the lives that were lost.
"Hopefully, we will manage to dive on the wreck of HMS Pathfinder 100 years to the day of her sinking. However, she lies upright in quite deep water. Her stern is at 68 metres while her decks are at 58 to 60 metres.
"This is for experienced sports divers."
