Her Swedish Majesty's Ship
Her Swedish Majesty's Ship or Hennes Svenska Majestäts Skepp abbreviated H.S.w.M.S. or H.S.w.M. Ship, is the ship prefix used for ships of the Swedish Navy (Svenska marinen) when the head of state is a female monarch. In English, this is sometimes used when abroad to differentiate Swedish vessels from those of the British Royal Navy.
In the Royal Swedish Navy, all vessels are given the prefix H.M.S. (Hennes Majestäts Skepp or Her Majesty's Ship). This is true for both surface and submarine vessels