Heckler & Koch P11 Country Germany Type Underwater pistol Manufacturer Heckler & Koch Introduction 1976 Specifications Weight 1.2 kg (2.7 lb) loaded Battery pack 700 g Length 200 mm (7.874 in) Width 60 mm (2.362 in) Cartridge about 100 mm (4 in) long, miniature solid-fuelled rocket with fins Caliber 7.62 mm x 36 Action Electric actuated Effective range 30 m in air, 10 to 15 m underwater Feed system 5 rounds, each in a barrel Sights 14.6 cm between sights

The HK P11 is a Heckler & Koch pistol designed as an underwater firearm. Since ordinary-shaped bullets are inaccurate and have a very short range when used underwater, this pistol fires steel darts about 10 cm long. It has five barrels, each of which is loaded with a cartridge, giving the gun a pepper-box appearance, and it is electrically ignited from a battery pack in the pistol grip. After firing all five cartridges, the barrel unit must be sent back to its manufacturer for reloading. It is very similar to its predecessor, the M1 Underwater Defense Gun.

The P11 is reportedly in service with German Kampfschwimmer and KSK, the British SBS, and 100 units issued to memebers of U.S. Special operations forces. It is also used by Dutch, Danish, Italian Navy COMSUBIN, Norwegian, French and Israeli combat divers.

In the past, Heckler & Koch has denied knowledge of its existence, but despite this the P11 has become relatively well-known, appearing in the 2003 film Tomb Raider: The Cradle of Life, and the 2002 video game James Bond 007: Nightfire.