In theory - yes, this would be possible, however highly unlikely.
After so many years, the boat would surely sustain damage from outside conditions and i.e. fishing.

Also, weaker elements such as valves and seals wouldn't last that long and flooding should soon fill the compartments inside the boat.

I would, however, entertain the notion that in such a submarine the internal compartments would be preserved in a much better shape than those of a sunken submarine where the hatches were opened and/or the hull was breached by an explosion of a depth charge.

Hope that helps,

- K.