It is armed with an underwater rifle.
Here s What You Need to Remember: Nerpa limitations would be battery life, as well as how fast it could move through the water, both of which are unknown. Equipped with only an APS underwater rifle would also limit the Nerpa’s utility against anything other than enemy swimmers or seals. No, not Navy SEALs, actual seals.
Conventional firearms are extremely ineffective underwater. Water exerts much more drag on an object than air, rapidly slowing down bullets underwater. Shooting at targets much more than about six feet away becomes next to impossible and not because of inaccuracy. Bullets simply tumble downwards and gently sink. This neat video shows why and is worth the watch. So, how to remedy this “drag” of a situation? Underwater rifles.