On the 1^st June 1939, H.M.S. THETIS sail out of the Mersey to Liverpool Bay on trials. On board were 103 persons. The submarine dived and never surfaced again. Due to some tragic mishaps and circumstances all but 4 on board were lost. The vessel was raised some 3 months after and beached on an Anglesey bay ( Traeth Bychan) where most of the bodies were removed. She was sailed to Holyhead where the remainder were brought out. 44 bodies were interned in a mass grave at Maes Hyfryd Cemetery in Holyhead. Artifacts are on display donated by the families of those lost. Thetis was refurbished and re-named THUNDERBOLT she was depth charged in the Mediterranean during the Second World War. There were no survivors                                                                                                     

              The"THETIS" having been raised and re-floated was beached at Traeth Bycan.

                     Preparing to recover the bodies from the THETIS at Traeth Bychan

                   THETIS renamed THUNDERBOLT depth charged during WW2           
                                      in the Mediterranean Sunk with all hands