HMS Dolphin (1924)

HMS Dolphin was a D-class submarine of the Royal Navy, launched in 1924. She was the first of the D-class and was significantly larger than previous British submarines, earning her the nickname "monster submarine." Her increased size allowed for a longer patrol range and a larger crew.

Dolphin was built by Chatham Dockyard and commissioned in 1925. She served primarily in the Atlantic and Mediterranean, participating in various exercises and patrols. During the early years of World War II, she conducted patrols in the North Sea and Atlantic, targeting German U-boats and surface vessels.

She was equipped with six 21-inch (533 mm) torpedo tubes and a 4-inch (102 mm) deck gun. She also carried mines, which could be deployed via special chutes.

Dolphin was withdrawn from active service in 1944 and was scrapped in 1945. While she did not score any confirmed U-boat kills, her presence contributed to the overall Allied effort against German submarine activity. Her design influenced later British submarine development, particularly in terms of size and endurance.