It looks like if they're upwind in a light breeze, the little air cooled gas generator is plugging away forward to the bridge deck.

Bizare. Aside from the CO, noise isues, I'd not be running a gas generator inside the boat in a compartment forward of me. I'll bet the extra "gas" is in a jug next to the damn thing.

We have a smallish, conventional 7.6 KW Westerbeke in our engine compartment between the two aft cabins. The compartment is sound shielded and the generator has a "soft shield" around it. It's pretty quiet below (and because it's a constant RPM unit) it's relatively easy to live with the hum. Outside, the only real noise is the water from the exhaust which is pretty quiet. NOT silent, on that starry, starry night; but probably not noticable within 20 yards or so unless there is no breeze.