I'd imagine you've seen this, but if not check the cool pictures and stories - pulling a t-34 tank and an ilyushin from a lake. Granted, not a dive but a recovery, but still cool. I'd be willing to spend a few zero viz dives retrieving a tank! Looks like a hell of a club. The first page is for the tank, follow the links to other articles.
Подъем танка (pulling tank) T-34.