The armed forces of a number of states of the world include units of combat swimmers and divers involved in underwater operations. Weapons for underwater shooting have been developed especially for such units.
Usually, units of frogmen and divers are strictly classified. It is very difficult to get into them, the number is small, which explains the low popularity of those types of weapons that are used in underwater reconnaissance and sabotage (or anti-sabotage) operations.
APS-5
APS-5 – a special underwater assault rifle – is still the most famous small arms used in the Navy’s PDSS. It was put into service back in Soviet times, back in 1975, but it was only declassified in 1993 at the international exhibition in Abu Dhabi.
APS-5 is capable of hitting a target at a distance of 30 meters at a depth of immersion of 5 m. At the same time, the firing range depends on the immersion depth. At a depth of 40 meters, it is only 10 meters. The machine itself was designed to combat underwater saboteurs and scouts of a potential enemy, as well as for self-defense against marine predators like sharks.
APS-5 can be fired with both single shots and bursts. It can also be used on land, but it is ineffective since the firing range in the air does not exceed 100 meters. This circumstance, by the way, forced the units of combat swimmers to issue the personnel with 2 submachine guns.
ADS
In 2013, the Russian Navy’s PDSS adopted the ADS, a special two-medium assault rifle. It is designed for shooting both underwater and on land. At the same time, the ADS is equipped with a switch for the operation modes of the “water / air” gas venting mechanism. The ADS has a detachable grenade launcher.
A bullet weighing 16 g, intended for firing under water, can penetrate a bulletproof vest and even the bottom of a small boat. The firing range under water, like that of the APS, depends on the depth of immersion: at a five-meter depth, the machine gun shoots at 25 meters, at a twenty-meter depth – at 18 meters.
When surfacing, an underwater saboteur may not pour water out of the barrel – it will fly out by itself during the first shot. Interestingly, the characteristics of the ADS in terms of use on land, in the air, are not worse than conventional small arms of 5.45 caliber. The under-barrel grenade launcher makes the machine even more attractive for submarine units.
SPP-1
A special underwater pistol was developed at the height of the Cold War – in the 1960s, and in 1971 its serial production began for the needs of the PDSS of the USSR Navy. It shoots long needle-shaped bullets with a caliber of 4.5 mm, while the lethal range of the pistol in the air is 20 m, and in water everything also depends on the depth of immersion: at a depth of 5 meters, the pistol shoots at a distance of up to 17 meters, when submerged at 40 meters – up to 6 meters.
The SPP-1 has a block of 4 smooth barrels. They recharge at the same time, the entire operation takes only 5 seconds, which greatly simplifies the implementation of the tasks under water. Separate cartridges would significantly increase the pistol firing time.
Р11 Heckler&Koch
The German-made pistol was also developed back in the mid-1970s. He entered service with submarine sabotage units of the naval forces of NATO countries – Germany, USA, Great Britain, Italy, Norway, France.
Distinctive characteristics of the weapon – a block of 5 barrels, each of which contains a 7.62 mm needle-shaped bullet. When all the bullets are used up, the barrel block is ejected. The firing range when submerged 30 meters is 15 meters, and on land you can hit the target at a 30-meter distance.
Z-84
The Star Z-84 submachine gun is produced in Spain by the Star company and is capable of successfully operating both under water and in the air, which makes it akin to the Russian ADS assault rifle. On land, the Z-84 is comparable in performance to most conventional submachine guns used in NATO armies. Under water, its characteristics are inferior to Russian weapons: the effective firing range of a submachine gun, even at shallow depths, is no more than 5 meters.
However, with a short range of fire, the Z-84 has one very significant advantage: it is equipped with standard 9 mm Parabellum cartridges, which eliminates the problems associated with the use of non-standard bullets in underwater weapons. The submachine gun is in service with the units of the Spanish Navy, other Spanish security forces, and is also supplied to other countries.
Thus, Russia (and earlier the USSR) is one of the world leaders in the field of high-quality underwater weapons. Indeed, in most foreign fleets, units of combat swimmers and divers are equipped with conventional machine guns, pistols, submachine guns, and special weapons.