Surface mounted exhaust backwash flap

[cygnusv]

Anyone know who has these for sale? Our exhaust has a decent swan neck, but the exhaust outlet is submerged. Sounds nice, but I worry that stopping in the water with rising water at the stern may flood the exhaust and possibly get into the engine. We're out the water end of March and I want to fit a flapper valve to the exhaust to protect the engine. Where the exhaust leaves the boat there is no space for a jubilee clip, so surface mounting is what I want to use. Any thoughts??

 

[sailorman]

Mine is under water when underway.
how old is the boat, if there has been no issues to date then it probably wont get flooded.
if you fix a flappy thing it may restrict the exhaust if under water

 

[cygnusv]

Mine is under water when underway.
how old is the boat, if there has been no issues to date then it probably wont get flooded.
if you fix a flappy thing it may restrict the exhaust if under water

The boat is 64 this year, mahogany on oak. We've added a lot of weight to her over the last 14 years living aboard. We are inland but are considering doing the Wash this summer. The boat's done it before (in 1972) but as I said, we've added weight. The engine is a big thumpy lump and I'm prepared to fit and test a flapper. Peace of mind for me really. The exhaust is under water all the time.