There were also APSS - Aero-Podvodny Samodvijushiysa Snaryad (Aero-Submarine Self-Propelled Projectie):
Essentially it was a midget sub, small enough to be hauled by large twin-hulled flying boat MK-1 (Mosrkoy Kreiser, aka Sea Cruiser). It was capable of lifting up to the 6 tons of payload, so midjet sub transportation was within its capabilities. The APSS was supposed to be hanged between the hulls of the flying boat, and thus could be airlifted into the operational area:
The interesting detail, is that APSS was supposed to be optionally-manned submarine. It was equipped with radio-control system, and fluorescent mix dispenser (so it could be traced underwater), and was supposed to be guided from the same MK-1 flying boat that delivered it to target. Of course, the manned use was also possible.
Two prototypes of APSS were build in 1935-1936, but demonstrated rather abysmal characterstics, and - most importantly - radio control system was not reliable enough. Also, MK-1 flying boat was, while capable, very expensive in building and maintenance. So, in 1936 the whole project was cancelled.