[jabl]

> Especially for sailing yachts, the exhaust is almost always wet (below the waterline).

I've seen quite a few sailing yachts, but never one with the exhaust below the waterline. Pretty low yes (typically maybe 10-20cm above the waterline?), but not below. When underway, the exhaust can be partially submerged due to waves.

'Wet exhaust' means that the engine cooling water is pumped into the exhaust pipe, which muffles the exhaust noise and cools the exhaust so that rubber tubing can be used.

[closewith]

> I've seen quite a few sailing yachts, but never one with the exhaust below the waterline.

To a rounding error, every luxury sailing yacht built in the last 20 years and most new designs of all classes will have underwater exhausts.

[jabl]

Merely repeating your previous statement isn't helpful. Thanks.

[closewith]

And your comment is?

The fact is that marine engine exhaust systems in good repair are not down-flooding points and certainly not on the yacht in question, where it almost certainly was below the waterline.

[jabl]

> And your comment is?

Merely expression surprise at your statement, considering my experience is so different. I have no experience of 'luxury' yachts though, just regular sailing boats. So maybe those superyachts are different?

> The fact is that marine engine exhaust systems in good repair are not down-flooding points and certainly not on the yacht in question, where it almost certainly was below the waterline.

Well I agree with that, but because, again in my experience, sailing yacht exhaust systems tend to have an S curve where the exhaust goes relatively high up. Whether the exhaust opening itself is just over or under the waterline doesn't really matter for downflooding.