Normally I would not have contributed to this thread but on our most recent cruise I came across boats running these generators for the first time. Don't know why I'd never seen them before but there it is. In two different anchorages I came across 4 of these generators, all on power boats. The obvious reason is that they have AC appliances and can't even make coffee without running the generator. And I'm here to tell you they are very, very loud when the generator is upwind and on the stern of the boat. Much, much louder than running an inboard diesel. And it's a different sound. Very high pitch like an angry chain saw. In the first case the boats were at least 100 yds away and they lit the thing off at 0700 and ran it at least 1-1/2 hours. It was loud at that distance. One guy had the thing sitting on his stern, kind of a lobster boat yacht. Completely destroys the peace of the anchorage. Just the other day I found myself downwind from another one only about 200 ft away. It was really unbearably loud and once again he lit the thing off early to make breakfast. I'm sure you wouldn't use it as I've described but I would not assume that it is only 3 db above ambient. There were other threads on this I've seen and most of the guys talked about running them around mid day when most folks are off to town or the beach, etc. And be ready for some ugly looks.