Won't go out of neutral

[tomjohnson]

I have a 1988 sea ray serrento. I took her out yesterday. She ran wonderfully. On the way back I slowed down then dropped to neutral while I awaited marina traffic. When I tried to go back in gear she just reved up. This was true when I tried reverse also. What can I do to fix this? Pictures also appreciated in descriptions of fixing it. thanks

[CDK]

Lots of possible causes but you must supply just a tiny bit of information.
What kind of control, engine, drive, recent service or repairs?