Dive boat exhaust

Folks I was on a large dive boat today and the 1st thing I noticed was the excessive presence of diesel exhaust fumes. Is this common on all boats? This was an older boat maybe it was just specific to this boat. I understand some exaust fumes based on how the wind blows but this boat seemed to move in a cloud of fumes?

I

Yummy.

Actually, they're not all like that.

Now a fishing boat... that's another story. Fishing just wouldn't be the same without a breakfast burrito over diesel to get me going in the AM.

K

Big problem of exhaust fumes getting pulled back into cabins and enclosed aft deck areas. This is a major cause of headaches and is actually carbon monoxide poisoning. Proper ventilation is required. A good hint is if the ensign (flag) on transom is blowing the wrong way back towards front of boat, instead of crisply aft.
Another very risky item recently in Boat US, is that molded swim plarforms, that people and particularly kids like to dive and swim under can have a high enough CO level to immediately cause one to pass out and drown. This occures at anchor when the generator is running supporting refridgeration, AC, etc.

Diesel exhaust can really knock one out. When I lived in Chicago, a trip downtown for more than about 5 hours caused me to getr the worst headache imaginable. I traced it to the diesel exgaust from the city buses.

I've gotten headaches and nausea from boat exhausts, so I always stay away from the stacks and plumes when diving on diesel powered boats. Less of a problem though because they are out in the fresh air.

Dr. Bill

You know when you are inhaling diesel. However, the exhaust from gas engines is not as objectionable, and carbon monoxide doesn't even smell.

"I love the smell of diesel in the morning!"

my father is a mechanic. diesel mechanics need a separate certification. well because you can die from the fumes. and not from prolonged exposure.

but man, that stench nauseates me!

some more than others.

At idle, most stink BADLY, because the exhaust has to be out of the water (this has to do with backpressure issues)

At cruise, many boats (the better designed ones anyway) are designed to SUBMERGE, either partially or fully, the exhaust ports. This tends to "duct" the exhaust away from the boat and occupants. Ditto if the ports are on the sides of the vessel rather than on the transom. The worst ones for "station-wagoning" are boats with stern exhaust ports that are dry at speed; if the ports are on the side they're in the slipstream and that tends to draw the exhaust clear of the vessel.

Gas boats are actually more dangerous to your health, however, because the exhaust DOESN'T stink and the CO will get 'ya without warning.

Larger vessels with dry stack exhausts have less trouble with this due to their high and dry exhaust plumbing. This arrangement is not common in recreational-sized (under 100') vessels though, primarily due to the insulation requirements and intrusion into the cabin spaces required to properly route it. For boats under 100' that are diesel-powered, virtually all are "wet" exhaust systems with the discharge at or near the waterline.

I love the smell of diesel in the morning...

Yeah, most of the boats I've been on will occasionally get you a whiff of exhaust. It SHOULDN'T be bad in the cabin, but if you're hanging out on the fantail somewhere you'll definitely get it...

Kinda sucks, but in a way it's one of the smells that reminds me of a fun day of diving out on the great lakes. Now, granted, if it were overpowering and constant it would drive me nuts....

When on boat with gas engines, be aware of the carbon monoxide symptoms. No objectionable smell need be detected.