Water in cylinders and no compression

[gregt]

I just had a water leak in my boat which took on a lot of water and flooded the engine. After pumping the water out of the boat, I had the engine pumped and electrics and carb replaced. All looked good. When attempting to start the engine, there was again water in the cylinders. Also, there now apprears to be no compression in cylinders 2 and 4. I assume the water was sucked in through the raw water intake and through the exhaust. The engine is fresh water cooled, so if it was a head gasket or water jacket - problems I've seen in other threads - I would expect antifeeze in the cylinders not water. Is there ay other possible source or way water would get into the cylinders in a fwc engine?