There is nothing at all wrong with removing the plugs and "cranking" the engine with the starter. Even if the crankcase is full of water, any additional damage to the bearings will be too minor to ever notice. This is not at all the same as getting it running with the plugs in and ignoring the oil condition, and that's not what anyone here was suggesting!
If the starter won't turn it, then use a socket on the damper bolt and a long handle and see if it turns by hand. If any water comes out of the spark plug holes, the the engine was hydro-locked and some connecting rods are almost certainly bent (engine is toast). Why not try to find this out as soon as possible?