An untouched 'time capsule' from the First World War lies at the bottom of the sea bed off Caernarfon Bay. It went down with the entire crew of twenty-six British Navy seamen.

Submarines are always silent and strange, and none more so than HMS H5 mistaken for a German enemy U-Boat and sunk by a British merchant ship on the 2nd March 1918. It lies 9.82-n.miles SSW of Holy Island in Caernarfon Bay. The merchant ship, the SS Rutherglen, later docked at Holyhead, Anglesey and reported sinking a German U-boat.

HMS H5 was overdue by four days and it became apparent that the merchant ship had actually struck a British submarine. The reality of what had happened was not revealed to the crew of SS Rutherglen or the families of those who died. It was some 50 years later before the tragic circumstances emerged.

H5 was struck in front of its Conning tower and sunk with the loss of the entire crew of twenty-six. Eye witness accounts say cries were heard in the water and a strong smell of petrol was also present. The British Admiralty ordered SS Rutherglen to leave the scene and never told the crew of the mistake. Instead, they were given a bounty for sinking a German U-boat. The truth only emerged years late,. The H5, which lies eight miles off Caernarfon, is recognised as a war grave by both the US and British governments.

Image: Nautical Reconstuction of a WW1 submarine upright on the seabed - courtesy of The Nautical Archeology Society

Location: Wreck lies 9.82-n.miles SSW of Holy Island in Caernarfon BayCaernarfon Bay

Location War Memorial : Hollyhead Maritime Museum, Beach Road, Holyhead, Isle of Anglesey LL65 1YD

Image: Nautical Reconstuction of a WW1 submarine upright on the seabed - courtesy of The Nautical Archeology Society