The German Heckler & Koch P11 Underwater Pistol

Underwater firearms are niche small arms, with a very specific primary purpose and only limited alternative applications. Following significant development of the concept in the 1960s and 1970s, specialised underwater firearms largely vanished from the armouries of most military diving and special operations units. But that does not mean that these weapons are not used today. As recently as 2021, Russian underwater firearms have been exported to foreign nations. The Heckler & Koch P11 underwater pistol, first adopted by the Bundeswehr in 1976, remains in service in Germany today, and is believed to be held in the arsenals of other countries as well. The research underpinning this note was compiled by the author over the last four years, and includes interviews with a number of knowledgeable confidential sources. The author hopes to present the most comprehensive insight into the capabilities of the P11 and its ammunition thus far published in English.