Thanks guys, looks like I won't bother trying this, just wondered if it was sensible but seems not. I think you are right dor, it doesn't plug into the inverter, will have to have a closer look. I have only used the generator with the shore line once and it worked fine but since it hasn't worked. The problem is the shoreline isn't long enough to reach where the generator is without moving the generator on the roof which isn't practical. The shoreline socket is at the front of the boat where the engine is and it seems a bit silly have it trailing the length of the boat (60 feet) if I got an extension. Anyway, first things first, getting the generator working the 230 in the first place! Thanks again people.
[edit] Also I have an extension cable anyway, will run this from the generator if needed for now, a lot safer me thinks.