Kmot,
There are several 'smoke generators' on the market. I can't make any recomendations cuz' I haven't used any of them. But, one of them should be small enough to get inside your boat. Then, just make the scale smoke generator ~on~ your boat the exit point for the 'real' generator ~in~ the boat. I'm sure there's someone here who'z used one, so 'they' need to speak up...
- 'Doc