Originally Posted by GeorgeC1
The generator impeller issue on charter boats I am convinced is because people run them while underway. You get a little rough water and the intake sucks Air. Does not take much to burn it up.
George... We never had a problem running the generator while underway. Intake was at a low point on the hull, near engine intake.

It's probably a bad after-market generator installation if you have problems with air getting sucked in.