sentences:  "Splendid" was detected by a German destroyer on 21 April 1943 while patrolling off Naples, Italy; the submarine was attacked with depth charges by the destroyer and forced to surface, after which she was scuttled and her surviving crew members taken prisoner.She was the most successful British submarine by tonnage sunk between November 1942 and May 1943.The S-class submarines were designed to patrol the restricted waters of the North Sea and the Mediterranean Sea.