The household CO detectors only go off at a pretty high percentage, which I guess is where they should cause nothing is worse than the boy crying wolf.
However as part of my job every aircraft I certify as part of the test flight I have to monitor
CO levels. I use a mini-SA portable gas detector.
So I carried this thing on my boat as I was curious and no matter where I put the Honda's (I did not try the bow as I had hatches open) I got detectable levels of CO.
CO is cumulative, that is it builds up in your blood over time, and levels that won't kill you or give you headaches or make you nauseous, will still affect your health
long term. Wasn't bad with my Son helping, but a Honda is more than my wife can handle and I can't get one out of the Lazarette and into the dinghy
However putting them in the dinghy
did four things, first no detectable CO, secondly that is the best place for the dinghy fuel tank
that I was using as an extended run tank anyway, thirdly it made it so that they could not be heard inside the boat at all, it was like being plugged into shore power
, and last if God forbid some how or another there was a fire, just loose the painter and let the dink go or fight it with a fire extinguisher, but likely the big boat would incur no damage.
Having been severely burned before by hydraulic fluid and almost burned alive, fire scares me more than just about anything, it was the worst pain I have ever felt.
But hauling the things in and out of the Lazarette and knowing there is gasoline in them was a real pain.
However I do concede that for many they are the best solution for AC power, and your just not going to get 1600 W any cheaper than you can with one, and at least the Honda seems to be very reliable and very easy to service
I am also one that believes that if you don't have a source of power to fully charge your bank pretty frequently, it will shorten it's life, LifePO being I guess the exception, I guess a LifePo boat can truly be a pure Solar