XT-Craft midget submarines,

The remains of two XT-Craft midget submarines, Aberlady Bay, Scotland, UK

The XT-Craft submarines are the training versions of the X-Craft that attacked the Battleship Tirpitz in September 1943. Two of these vessels were transported to Aberlady Bay and used for target practice and gun tests by Royal Air Force aircraft.

(via BikELove-Scotland and Coast Kid)