Front view of the Sallyport Hotel, Portsmouth, where Lieutenant Commander Lionel Kenneth Phillip 'Buster' Crabb (1909-1956) stayed on the night of 18/19 April 1956. Crabb was a British Royal Naval frogman and MI6 diver (some would say sabotage agent and alleged double agent), who disappeared during a reconnaissance mission investigating the Soviet cruiser Ordzhonikidze in Portsmouth Harbour. A body was found months later, but it was difficult to identify as the head and hands were missing.