Just went to Cedar Point and back with no issues, went to the beach yesterday and when it came time to dock surprise, starboard drive will not shift to reverse. It goes into neutral and forward fine, but the shifter will not move into reverse at all like something is stopping the cable.

Suggestions on where to start, at the helm, pull the drive, etc.
Thanks

Could be a couple things, First disconnect the upper shift cable ,see if you can shift into both gears with eng. idling connected to the hose, if you can get both gears may be just a cable adjustment , if not, remove the back cover on the drive, see if you can shift it manually ,,,with the eng. shut off of course,, I have seen the shift shaft screws break off so they only shift into reverse or forward,, the shift cam or linkage may be worn down ,, or it could be the cone clutch worn too thin,, several things to look at one at a time.
Each one I repair for my customers have something different fail it seems.
Good Luck.