Re: Atomic 4
My previous boat, recently sold, had an A4. They are good, solid, simple engines. One advantage is that the A4 is a lot quieter than most diesels. The gas fumes thing is no different than carrying propane. Follow proper procedures, and maintain the system, and it's no big deal.
The major downside of A4s is really just a reality about gas vs diesel: diesel is roughly twice as efficient. If range is not an issue (not going long distances, into areas where fuel is hard to find), then the A4 can be a fine engine. If range is important, go with diesel.
Why go fast, when you can go slow.