HMS Alliance

HMS Alliance is a Royal Navy A-class, Amphion-class or Acheron-class submarine, laid down towards the end of the Second World War and completed in 1947. The submarine is the only surviving example of the class, having been a memorial and museum ship since 1981.

The Amphion-class submarines were designed for use in the Far East, where the size of the Pacific Ocean made long-range, high surface speed and relative comfort for the crew important features to allow for much larger patrol areas and longer periods at sea than British submarines operating in the Atlantic or Mediterranean had to contend with. Alliance was one of the seven A-class boats completed with a snort mast - the other boats all had masts fitted by 1949.

Source: Wikipedia