Mark & Debbie Mueller
To try and mitigate this problem a 12 V normally open (NO) valve could be connected to the muffler drain. 12 V power can be obtained from a ship’s system such as the engine exhaust fan that only operates when the engine is running. When the engine runs and the valve is energized, it will close blocking the drain line and keeping the engine exhaust contained; with the engine off and power removed the valve would return to its NO position and allow any water in the muffler or any water that subsequently enters the muffler to drain to the bilge. Ahead of the solenoid valve I would install a manual ball valve as a backup in case the solenoid fails and not knowing what kind of contaminants are in the muffler consider installing a small filter.
I ran this idea by another forum member that is very knowledgeable about all things Amel. His comment was “Do you think your idea is childproof?”. It is not completely childproof since it is an active system however it is a way to mitigate the problem and I believe follows the KISS principle. Additionally, it would be relatively inexpensive to implement while providing an alternative safeguard for the very expensive engine repair.
Brass Ring A54