Unlikely, since that's drinking water! More likely that your engine can heat that water, giving you hot water.
You should have a seperate cooling system running to a skin tank on the inside of the hull. It does sound like your engine has overheated which can cause problems and then you tried to run the engine again without addressing them. The most likely cause of overheating is a lack of water in the cooling system. You need to locate the pressure cap above the water reservoir, undo it and check the water level inside. If there's no water, then that's the problem. The cause could be a leak in the system somewhere or possibly a worn out pressure cap. Over heating could split the head gasket too so check inside the oil filler cap to see if the oil has turned into something akin to mayonnaise which would indicate water getting into places it shouldn't.
The good news is that bmcs are tough old beasts and can usually be coaxed back into life.