The 10th Submarine Flotilla was a Royal Navy submarine formation during World War I and during World War II
HMS Una one of the 10th Submarine Flotilla boats
HMS Rorqual and Thunderbolt mooring up at Malta's submarine base in 1943
HMS Upholder (P37) was a Royal Navy U-class submarine built by Vickers-Armstrong at Barrow-in-Furness. She was laid down on 30 October 1939, launched on 8 July 1940 by Mrs. Doris Thompson, wife of a director of the builders. The submarine was commissioned on 31 October 1940. She was one of four U-class submarines which had two external torpedo tubes at the bows in addition to the 4 internal ones fitted to all boats. They were excluded from the others because they interfered with depth-keeping at periscope depth.
HMS Upholder
Image: UPHOLDER badge 1 1
The Italian cargo ship Tembien, which Upholder sank in 1942 with the loss of almost 500 men
Italian torpedo boat Pegaso, which may have sunk HMS Upholder off Tripoli