Excessive Exhaust in Cabin and Cockpit While Underway

I'm getting an excessive amount of exhaust smell while underway. Seems like it's always been this way but wife seems to think it's getting worse. We did a 50 mile run yesterday from California Delta to SF Bay. While at cruising speed (with windshield vent and center Eisenglass piece open) there was a strong exhaust smell which we figured was coming from exhaust ports at rear of boat. After about an hour, CO2 alarm in cabin went off (door was open) and we grabbed it and brought it into cockpit area where it eventually went off but strong smell continued. Finally I shut the cabin door and smell immediately improved but was till too strong for my wife. There are some openings in the area around the stereo inside the cabin that I believe is open to engine room so I will look to seal that up, but why would there be that much exhaust coming from engine room in first place - leak somewhere or is that normal? I would assume all exhaust should be heading out the back of the boat. Looking forward to everyone's feedback.

If I were a betting man it's your extended sun shade creating this problem. Try pulling that down for a quick run and see if you notice a difference before you start looking for leaks in your cabin walls.

Stee6043 said:

If I were a betting man it's your extended sun shade creating this problem. Try pulling that down for a quick run and see if you notice a difference before you start looking for leaks in your cabin walls.

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Agree, we have an extended canvas camper cover that seems to accentuate the "station wagon effect". If you have the cabin door open, it will draw CO down there. If you open a hatch or two down there, you'll have positive pressure to move air thru the cabin. We usually run with the door shut, and as you did, with the vent and middle clear section open.

curious - assuming you have household smoke/co detectors? last week about two hours into a four hour ride the ones I have in the cabin (residential units) also went off. Figured it was low levels but prolonged duration that set them off - as the wind curls around the boat inevitably bringing some of that exhaust in.

Curious if there is a preferred way to run the boat (windows/doors/vents) to limit/eliminate the co.

Also, does anyone with true official marine detectors have the same problem?

Close your center windshield vent and see if that helps. Our Tiara drew exhaust into the helm when that was open. It was less of an issue with it closed. We finally moved our exhausts from the transom to underwater and that solved the problem completely.

isn't the door to the cabin below supposed to be closed (while underway) for this reason. I was thinking there is a sticker on mine that says that.... Station Wagon effect