2015 SE450 starting problem

My starting circuit has developed an intermittent problem that now appears to be permanent. Starter fails to turn over, no clicks, nothing. Batteries are both new and fully charged. Lanard and gearshift switches working fine. Boat has 203 hours and starter was new 50 hours ago, so don't think it is the problem. I speculate that there is some sensing/control circuitry that is preventing voltage from appearing at the starter, but not sure. Cant find electrical wiring diagrams anywhere to troubleshoot. Engine is Indmar 440. Ideas and troubleshooting suggestions welcome! To complicate things more, the starter is almost inaccessible underneath this engine, not sure just how serviceable it may be without pulling the ngine out of boat.

Check you starter solenoid and try checking your nuetral safety switch. If either fail they will cause the same issue you are having

I think we have narrowed it down to starter, going to replace starter/solenoid. Thanks for responding!