John,Bringing this one back up as it's a good idea for my Duffy, I want to try and keep the stern clean, with less soot and this seems like a great solution. @Blitzen do you have any pictures of your 36 or the new boat's underwater outlets? I'm curious how much of a lip is used to create a good vacuum while cruising ahead.
Don, the look of the faces when I would tell people the HP of the engine and then they looked down and see the exhaust port on the stern. They would give me a blank look and say oh yeah, ok and walk away scratching their head like I was the crazy one. I am sure they were thinking that there was no way I had that much HP with that little exhaust line in the transom.Not to mention all those folks that ask, "Where the hell is your exhaust" And you say, well it's up on the house top where no one can see it.
I owned a 28 express. The under water design was an opening above the recessed trim tabs. It also had an oval slot in the transom for when the tabs were pulled up. I loved it. Henriques also incorporated a water lift muffler design into the exit. Very quiet. I'm a Marlin guy and the boat raised Marlin better than any other boat I owned. I believe BFT are more sight hunters and any noise is irrelevant.every henriques I have seen has under water exhausts, know a bunch of owners who do well tuna fishing
my only concern would be introducing air and a bubble stream ahead of the prop.
Have no fear. The box that the underwater exhaust goes thru has a small seperate pressurized compartment. On top side of the compartment is a small tube that is tied into the. 2" above water line exhaust so you can see the water coming out.One downside would be not being able to see or maybe hear whether raw cooling water is pumping through the exchanger into the exhaust. My GM 26 has a diverter at the transom that directs the exhaust to a point a few inches below the waterline. I miss not being able to hear and see the raw water exiting the exhaust just so I know immediately if there is a problem with the raw water cooling loop. (Are those diverter units really useful? Should I take it off?)