The HK P11 is one of the least known weapons to emerge from the Heckler & Koch factory. Developed during the early 1970s to arm frogmen (combat divers), this weapon is apparently in use with the Navies of Germany, Italy, France, Norway, the UK and the USA. This highly unusual weapon is probably the only serious rival to the Soviet underwater pistol, which appeared in late 1960s. The P11 and its ammunition is somewhat bulkier than its Soviet counterparts (the SPP-1M), but, on the other hand, the P11 has one round more capacity and a larger caliber, probably resulting in better lethality.