Just wrote an article on this..
You could run a boat on propane, but I think CNG would be safer. Either would require an extensive reworking of your fuel delivery system by a CNG/LP qualified mechanic. You would also add a good bit of weight for the tank, plus you would have the age old problem - how do you carry enough fuel? In addition, CNG engines are only efficient when using very high compression, so a gas engine conversion usually results in an in-efficient CNG engine. You would need to find a fueling station that could compress enough CNG to fill your tank quickly (faster than 20 or 30 min or so depending on tank size, which tends to be LARGE (another problem)). I was looking into re-powering my truck to run on CNG - what a nightmare. It is a great idea in theory, but our technology is just not there yet. Plus, our infrastructure is not there either. The pipeline exists, but the compressing stations do not. Don't forget about refueling at sea if you run out - a nightmare. Unfortunately, we are stuck with dirty fuel for the time-being. Good news is that good stewardship of the land and sea will go a long way. Owning and running a fourstroke engine should be first on your list if you are truly environmentally concious. Much less pollution than a two stroke. Best Regards, Rob
