Underwater firearm

Underwater firearms or needleguns usually fire flechettes or spear-like bolts instead of standard bullets.

[citation needed] Underwater firearms were first developed in the 1960s during the Cold War as a way to arm combat divers.

First fielded by the Russian special forces in 2000, the folding-stock ASM-DT amphibious rifle is capable of firing two kinds of ammunition, both of 5.45 mm caliber: When used against underwater targets, an underwater firearm may have a longer range and more penetrating power than spearguns.

This is useful in such situations as shooting an underwater intruder where the projectile may have to first penetrate a reinforced dry suit, or a protective helmet (whether air-holding or not), or a thick tough part of their breathing set and its harness, or the plastic casing or transparent cover of a small underwater vehicle.

Supercavitating ammunition that functions better underwater has been developed by Defence & Security Group (DSG), a Norwegian company.