The quickest way to get water out of a hydrolocked engine is by removing the spark plugs and attempting to start the engine. As the engine spins, the pistons should start to move again and force the water out of the holes in the cylinder heads where the spark plugs would normally be. Once all the water has been removed, the spark plugs can be replaced — although you might need to replace them with new ones. As long as no internal corrosion has occurred, your engine might start and run like normal. You should also go ahead and change the oil since water is likely to have gotten mixed with your oil as well.