Underwater Weaponry v2

A revamp of my original (and lackluster) post. Enjoy.


Although standard rounds do in fact work underwater, their performance is extremely hindered. Surprisingly, subsonic ammunition actually works better underwater, with an effective range of around 2.4 meters (8 feet) before slowing to non-lethal speeds compared to the 90 centimeters (3 feet) before supersonic ammunition disintegrates. Taking this into account, normal firearms are nearly useless in aquatic environments.

Surprisingly, weapons such as bows and crossbows actually perform better than firearms when submerged despite the drag factor due to arrows having a more streamlined design.

Special ammunition known as supercavitating ammunition has been developed which function significantly better underwater, however these rounds are limited to a select few cartridges, which are 5.56×45mm, 7.62×51mm, and .50 BMG. Despite their rarity however, these should still be considered.

TL;DR, if you’re underwater just ignore firearms entirely, it’s not worth it and you’re going to waste tons of ammo. Use a specially designed underwater weapon like the ones below, or if those aren’t available use a crossbow or bow.

Possible Weapons

(Please note that these are all just suggestions for reference and are to be taken with a grain of salt)

Heckler & Koch P11


A rather peculiar five-barreled German-designed underwater firearm which fires 7.62×36mm projectiles, which are electronically actuated from a battery pack in the pistol grip. However, after firing all five cartridges the weapon must be sent back to the factory for reloading, effectively making it a single-use weapon.



A break-action, four-barreled pistol developed by the Soviet Union for use by frogmen and underwater demolition teams, the SPP-1M fires a 4.5×40mmR steel dart that is somewhat innacurate when fired out of water due to it requiring hydrodynamic effects to stabilize the round underwater.



The Soviet-designed Avtomat Podvodny Spetsialnyy, or “special underwater assault rifle,” was designed to supplement the SPP-1 pistol and uses a 5.66×39mm cartridge in 26-round magazines. However, the weapon was extremely innacurate and the service life of the rifle was only 180 rounds when fired out of water.


The replacement for the APS assault rifle, the ADS is a bullpup layout rifle that can accept both standard 5.45×39mm ammunition and underwater ammunition, and also has an integral 40mm grenade launcher (it is not known whether or not this can also fire underwater). Unlike its predecessors, however, it can also accept suppressors and optics due to a Picatinny rail.

DP-64 Nepryadva

A Russian-designed special-purpose double-barreled 45mm grenade launcher designed to defend coastal installations from combat divers and naval special forces. Its grenades behave much like conventional depth charges and explode upon reaching a certain depth in order to maximize its lethal potential against submerged personnel. It can use fragmentation, flare, and concussive grendes.

Mk1 Mod 0 UDG

Developed at the United States Naval Surface Weapons Center, the UDG is a six-shot pepperbox-type revolving handgun developed for use by naval special forces. Unlike other underwater firearms, however, the self-contained design of the cartridge eliminates muzzle flash and reduces sound, making it also an integrally suppressed firearm.



Also known as a “bang stick” or “shark stick,” a powerhead is a specialized contact-type firearm which is designed to be attatched to the end of a spear, and can be modified to use a wide variety of cartridges, from 12 gauge shotshells to .357 Magnum. By firing while in contact of the target, the round does not expend any kinetic energy travelling and thus is nearly unaffected by the usual penalties that a normal firearm suffers from when fired underwater.



An air-powered weapon relying on air pressure in order to fire a projectile at high speeds (note that I decided to suggest a pneumatic speargun instead of a band speargun as the latter would be too similar to a crossbow).

Alright, this doesn’t nearly have enough meat and potatoes as many of many of my other posts and is really just a glorified weapon suggestion post, but the regular badge doesn’t pay for itself, and I have to meet quota. That being said please leave any suggestions and concerns below.


If there is decent underwater environment, this could live. Otherwise, there is no point to do that.

1 Like

Maybe it’s just to fill the environment? Having diving masks in diving places is nice.
But it is still useless in the game

I think anything more than a speargun is overkill, though Id love to see stuff like diving tanks increasing oxygen and stuff to loot underwater(though this is up to mapmakers) could be fun to stab a shark that came out of nowhere.


Only spear guns. The rest is very unnecessary.


Having a special gun that can fire special underwater ammunition, but still feeds that ammunition out of regular AK-74 mags could be problematic. What even happens when you shove that ammo in a regular AK-74? If you think there’s a place in the meta that will absolutely need to be filled by a gun that can fire both underwater ammunition and modern Russian assault rifle ammunition, I’d say it would be better to base it off of the ASM-DT and have the underwater ammunition fit in a different type of magazine than the standard AK-74 magazine. I’d also recommend simplifying the amount of ammunition types by treating the cartridges of the ASM-DT, of the APS, and perhaps even of the SPP-1 as knecked up/down versions of the same cartridge if not fully interchangeable.

If shoulder fired grenade and rocket launchers make an appearance in Unturned II, then I think the DP-64 would definitely distinct enough among them to make an appearance.

The Mk1 Mod 0 SDG UDG I could only see having a place in the game if one or more other weapons with sealed piston in their cartridges were included, such as the

Longer list of examples than I originally intended to type

AAI QSPR or OTs-38 revolvers, the TKB-506 or S4M disposable pistols, the NRS-2 pistol knife, the PSS selfloading pistol, or the MSP derringer.

Maybe instead of making the HK P11 completely useless after firing 5 shots, you should be able to replace the barrel cluster (although refilling barrel clusters would either be impossible or take a very skilled mechanic.)


Good points.

I still like the ADS better than the ASM-DT though.

the DP-64 is cool, you could troll people at the beach with it

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