CO danger in aft cockpit while underway

[sbu22]

Again, for the cost of CO (and smoke) detectors, why take the chance?

CO exposure is a classic "low probability - high consequence" event. In 12 years, my 43' gasser with 4 interior smoke/CO detectors has never had a CO trigger - legitimate or not. In my business, I have access to calibrated reference CO gas mix - never an issue with the CO channel when checked annually. The smoke detectors seem to get wonkey at the 2-3 year mark (high RH environment?), so I replace them all at that interval. For an amortized cost of $75-80/year, well worth it.

 

[Browny]

We have a Sport Fish style Hatt with old thirsty big blocks. It has "underwater" exhaust out the of the hull sides right above the cockpit. Our CO detector will go off almost 100% of the time when idling the dock, warming the engines up. Its annoying, but I've never felt that anyone was in any danger.

We troll up and down wind all the time, cruise with the the salon doors open, and there is always someone in the cockpit while underway enjoying the view. We crossed both lake Erie and Ontario, and the Erie Canal to get the boat home, and everyone lived to tell the story. The only time we're unable to "get away" from the fumes was in the locks, but even then it was tolerable. Other than that, if needed, open the front hatch and enjoy the breeze.

I'm on the team of know the risks and use your brain. I had no idea that John, guy in pic below, was risking his life while enjoying his drink in the cockpit.

Of all the hobbies I'm involved in, I can assure you that the CO in the cockpit, or salon, while underway will not be what takes me out lol.

 

[dannc]

Years ago a coworker and her family were out skying and wake boarding. My coworker and young child were sitting at the stern of the boat when the child passed out and fall into the water. They were near the exhaust. The adult was not bothered because they were a bit farther from the exhaust and maybe had more mass. The child was much closer to the exhaust.

Thankfully, the child had on a PFD, other wise she most likely would have drowned, and would have been a statistic. The mother was able to quickly grab the PFD, pull the kid back on board, and the kid recovered just fine.

They never sat that close to the exhaust again.

Later,
Dan

 

[TBill36]

Big desels when running at cruise when underway will cause a pressure delta between the engine room and inner cabin. Any leaks between the 2 cause air to be drawn from the cabin into the engine room. Leaving the salon door open can then cause salt air and any exhaust products to be drawn into the cabin causing additional corrosion and unpleasant breathing.

 

[rslifkin]

Big desels when running at cruise when underway will cause a pressure delta between the engine room and inner cabin. Any leaks between the 2 cause air to be drawn from the cabin into the engine room. Leaving the salon door open can then cause salt air and any exhaust products to be drawn into the cabin causing additional corrosion and unpleasant breathing.

If the engine room is under enough of a vacuum to cause that through just small air leaks between the spaces, then the engine room ventilation is majorly insufficient.

 

[Comodave]

Big desels when running at cruise when underway will cause a pressure delta between the engine room and inner cabin. Any leaks between the 2 cause air to be drawn from the cabin into the engine room. Leaving the salon door open can then cause salt air and any exhaust products to be drawn into the cabin causing additional corrosion and unpleasant breathing.

Typically diesels don’t produce enough CO to be very dangerous. Not impossible, just unlikely.

 

[Comodave]

I have a CO/smoke detector in the cabin. It's only gone off once, as I was leaving the dock, backing into a slight breeze with the salon door open.

I'm not concerned about CO in an open cockpit, but I will make it a practice to keep the salon door closed when the engines are running.

Usually one good way to mitigate the “station wagon effect” is to open some forward facing hatches and open the salon door to allow air to flow through the boat and break the low pressure area in the cockpit.

 

[psneeld]

If the engine room is under enough of a vacuum to cause that through just small air leaks between the spaces, then the engine room ventilation is majorly insufficient.

This site has people looking for problems that are only supported by statistics or one in a million stories (which many I would love to hear the whole/real story) if presented in another way would barely get a nod by the people I know.

So many topics become a pile on because to do so is PC/the cool thing/ seemingly intelligent answer and the only reasons I can think of mainly don't have a lot to do with the topic.

Have been on many a sportfish or flybridge sedan boats with the sliders open and yes occasionally it can be bad, but most I know will just change something enough to mitigate or eliminate the effect. If that much salt spray compared to overall operations is generated to worry about corrosion...suggest some exhaust/intake changes.

NOT using a cockpit on a boat with one designed almost around it or having to shut sliders/exterior doors on a pleasant day seems a bit criminal to me and 99% of the time completely unnecessary. YES...have a CO detector nearby.

 

[rslifkin]

The big thing with CO risk is that 2 very similar, but not identical boats can experience very different behavior. Slightly different exhaust placement, slight differences in how air flows around the boat, etc. can all make a big difference. So the best thing to do is put detectors in areas of concern and monitor for a problem. Some boats will be very prone to drawing fumes in, others will only do it under very specific conditions.

 

[Comodave]

I was thinking along that line. A danger exists but so small it is not worth worrying about. What about urban commuters who spend hours a day in stop and go traffic? I would think C02 concentration to be higher sitting in traffic than in the cockpit of my boat. In my limited experience of 7 decades I don't recall a reported issue sitting in a cockpit.

See my post #18. Several of the people that had pretty severe CO problems were in the open cockpit of the boat, the rest were in the cabin. Just because you are outside doesn’t relieve you of the danger of CO poisoning. You need to break the low pressure area in the cockpit by possibly opening some forward facing hatches and cabin door. That may break the station wagon effect of low pressure that sucks the exhaust fumes up into the cockpit. Some people may be sitting next to you and pass out and you may not experience any symptoms.

 

[catalinajack]

Awareness of about 99.99% of dangers in life will keep you out of trouble.

The reoccurring statement from people in bad situations is usually "I never knew........."

This site is a haven for fearmongering........ people who seem to be worried about pretty obvious things that are no big deal for the average intelligent person who bothers to do a little research on their chosen hobby.

I include the perceived need for fuel polishing as "fearmongering."

 

[North Baltic sea]

I am safety oriented........ must have something to do with my career and training
Why risk CO poisoning. It can be deadly, and often victims don't even notice they are slowly being "gassed"!! It binds to human hemoglobulin better than O2 and does not dissipate easily once in the bloodstream, hence effective onboard treatment can be less than effective and/or take a long time (for symptoms to relieve).

Good advice from the others in my opinion...... keep the rear openings closed and also install CO detectors. We had side Pilothouse doors in our Nordic, and we often had them open while underway. This provided a pretty good cross draft, we never smelt diesel exhaust, and the CO alarms never went off. We always kept the rear windows and rear door closed when underway or even with the engine running.

CO is not something to take lightly (not saying you are, just advising).

Hi, we have the same boat, the wind behind and it's faster than you usually causes me a problem keeping the starboard door open because the diesel exhaust gets inside.


It is also worth noting the diesel particles that expose health, for example cancer, so it is not worth taking the risk of inhaling exhaust gas.


NBs