I’m spending the night on the boat, as I try to do a couple times a week. It is in the lowish 30s. I’m snug as a bug in a rug when, quite rudely at 0400, I am woken by the insistent chirp chirp chirp chirp of my Fireboy-Xintex Carbon Monoxide Detector. Shit. I tumble out of bed, open the hatches (brrr), and start the fans. The alarm happily silences after about fifteen or twenty minutes.

What the hell just happened?

The boat is being heated with a 700 watt miniature radiator style Homebasix CYPB-7 Mini Oil Filled Radiator, which seems a bit undersized, so I supplemented with a little ceramic Holmes HFH103-UM Compact Heater Fan. It is electric heat and shouldn’t generate any carbon monoxide. I did light the lantern for awhile last night, and I cooked dinner onboard, but given the hours that have passed, I don’t think they could really be a factor either. When opening the hatches I listened carefully for any sounds of generators or engines. Nothing. The marina is a ghost town. Where did the CO come from?

Besides the mysterious introduction of CO to the cabin, I wonder why it lingered. I have a cockpit enclosure but there are big areas for ventilation as it attaches to a taffrail that is five inches off the deck. Surely there is more than enough air exchange. I do have some curtains in the cabin to close off the main area from the galley/navigation area, and from the head in order to contain warmth (and, I guess CO); but they are several inches off the sole to aid compartment to compartment ventilation (and, being curtains, aren’t exactly air tight). The top drop board has about 60 square inches of screened opening protected with a rain shield, and a one inch gap between the top board and the sliding hatch. I would think this is plenty of ventilation. I have only a small solar vent in the forward head, so perhaps there is inadequate through venting, but the total lack of interior condensation suggests to me that the whole ventilation is working fairly well.

I had a very minor headache, that eased over an hour or so; but I’m not sure if that is from CO poisoning or from waking up hours before normal. I’m prone to headaches, normally, so I’m not terribly confident in using them as a symptom. I don’t have any other symptoms that I can associate with CO poisoning.

Best guess: somewhere out there someone is running an engine, generator or heater, and somehow the CO managed to make its’ way to my boat and get sucked in through the cockpit enclosure and into the cabin. It seems rather unlikely; but what else can it be?

I’m now snuggled in my bunk warming up with a healthy new paranoia. I’m leaving the curtains open and the top drop board out to increase the airflow, suddenly comfortable with the chill of a cold morning and happy that I went to the hassle and expense of installing the CO detector. I’m not sure how dangerous things really were; but figure since I woke up readily without any disorientation (strangely, not even the usual morning just awake groggy disorientation) or other significant symptom (outside of the questionable headache) I tend to feel the levels may have been unhealthy, but not yet critical. However, since dying in my sleep would be a significant detriment to the adventures I have planned, I am glad the detector is there and working.

Carbon Monoxide Poisoning Symptoms:

• Dull headache
• Weakness
• Dizziness
• Nausea
• Vomiting
• Shortness of breath
• Confusion
• Blurred vision
• Loss of consciousness