I agree that it's important to be aware of, and manage, your risks. But portable generators DO impose different risks than a properly installed genny. For one, when at anchor, boats will always face into the wind. Putting the genny on the bow means the wind will blow the exhaust toward the cabin, where you are sleeping. The exhaust will find it it's way in through - whether through small cracks in deck hatches or by the "station wagon" effect... down into the cockpit and will then actually go FORWARD through the cabin door. This EXACT scenario HAS happened in real life.
Second, an installed genny will exhaust out in one of two places: through the hull side, just above the waterline near the stern or underwater. Both of those locations allow for the breeze to carry the exhaust away from the boat.
Thirdly, you still have the electrical issues (read below).
Have you checked the condition of your CO monitor, by the way? They do expire.
These, below, are not my words... I had copied them from another forum and pasted here - written by a gentleman much more knowledgeable than me:
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PORTABLE GENERATORS ON BOATS
Carbon Monoxide
Is simple to grasp, breathe it in a confined space and you don’t wake up. Permanently mounted marine generators have their exhausts plumbed to exit at or very near the waterline and away from closed occupied spaces.
Uncontained Fuel System Vents
The fuel systems on Honda and other portable generators are vented to the atmosphere and their carburetors have a bowl drain that releases fuel inside the generator case. That means where you run it, store it or put it under way will have gasoline fumes released in the area and if the bowl drain leaks, you have raw fuel spilled and an explosive liquid in the compartment with the generator.
Lack of ignition protection on electrical devices
The electrical components on portables are not ignition protected like marine generator electrical components are. This means you could easily have an arc or spark anytime contact opens or closes or whenever something is plugged in or disconnected.
Lack of Continuous Grounding
Portable generators pose an additional shock hazard since the portable is not grounded to the boat or to a shore side ground. Likely not a problem with a drill or power tool, but if you connect it to your boat's AC system, you have essentially disconnected the green wire.
The Honda iU series generators are inverters. An inverter drives both line and neutral so it is possible to have voltage between neutral and ground. With ground bonded the the boat's bonding system, which mean to the water, this means a shock hazard may exist that normally would not. Anyone who ignores all the above risks and insists on using a portable generator should use a very good, sensitive multi-meter to throughly prove out the electrical system. That the reverse polarity light is lit is clear indication of a potential problem.
The USCG governs only boat manufacturers and the manufacturers voluntarily subscribe to ABYC guidelines, so there is no "law" against using portable generators on boats. However, both the USCG and ABYC say using portable generators on boat is a bad idea and regularly caution boaters against it.
In spite of the fact that Honda’s advertising says that boating is a popular use of their generators, They have not addressed the grounding, gas fume and ignition protection issues and those risks do indeed exist.
If you are one of those who jumped on the CO train and the relatively few deaths attributed to CO, you are not fully considering all the risks of using portable generators on a boat. While accidents may be rare, you do substantially increase your risk of becoming a "statistic" when using a portable generator on a boat.......you put your family unnecessarily at risk when you do.