So what's the solution ? Assign a surveillance UAV to every Russian ship parked "without a good reason" over a cable ? It would be expensive, but doable, and create a reserve of vehicles for wartime use.
replies(13):
http://www.hisutton.com/Yantar.html
http://www.hisutton.com/Belgorod-Class-Submarine.html
http://www.hisutton.com/Russian-Spy-Submarine-BS-64e.html
and so on