Our boat (1958 Chris Craft) has a straight-6 inboard that
is raw water cooled. The exhaust exits just at the water line.
It's not too loud for me, but some of my guests seem to
find it loud. ~ What options do I have for muffling it?

I'm thinking along the lines of an elbow that could be
mounted on the transom to pipe the exhaust under
water. This would not look original and I have to
wrestle with whether I care about that or not. But
assuming I feel it's worth the noise-reduction,
would that work?

Thoughts?

Thanks,
Gary