Need Help w/ Issue with Glander Cay Exhaust Below Waterline

I have a 23 Glander Cay that has the engine, exhaust and exhaust pipe below the water line. The water appears to be filling up the exhaust tank and pushing back to the engine. I just blew up my new Yanmar.

Does anyone know how to solve this problem? Short of installing a check valve or vented loop?

Sorry to hear about your engine. This video may help you see what’s missing - or what may be going wrong - with your setup. Why is your exhaust pipe below the waterline?