The rising threat of attacks by
frogmen in naval bases caused various
anti-frogman techniques to be developed. In the
USSR, one of these techniques was
guard frogmen sent to stop the attackers. At first these guard frogmen were armed only with
knives and
AK-type rifles. The rifle was carried in a waterproof case and could be used only on the surface, so the only effective underwater weapon against enemy frogmen was the knife. The
SPP-1 underwater pistol was accepted in 1971, The APS was adopted in 1975. Afterwards, there was lengthy improvement work on the APS. One improvement was fitting a perforated gas pipe with a special shield to break up the emitted gas bubbles, making targeting easier and reducing the visibility of the bubbles, allowing stealthier firing of the weapon. In 2021, Rosoboronexport reported the delivery of APS rifles to a foreign country. Due to the limitations of the APS such as being ineffective when being used outside of water, the
ASM-DT was designed to address them. ==Design==