A gen-set should also fit the available space and still provide room for servicing. There are several ultra-compact models on the market for especially tight areas or smaller boats. Weight and placement are also concerns, as each can affect boat performance. Another consideration is operating speed. Fuel type is also important.
Most boaters simply choose a gen-set that uses the same fuel as their main engines.
In these cases, the diesel gen-set must be certified as having no components that could ignite gasoline fumes. Diesel fuel is also less flammable and doesn't produce carbon monoxide when burned. Another buying concern is availability of parts, especially for boaters who cruise long distances. One of the final concerns is cost. There are many approaches to spending money on a gen-set.