Other than cutting a really big hole in the back of your boat
why not enlist the help of the Admiral or one of those deck hands that always seem to be around when you don't need them. You can "supervise"...the way any good Captain would to make sure it's done right. Just a thought.
Or...have you tried a pair of BBQ tongs to reach in there instead of your entire arm?
OK...I'm out of "thoughts"...good luck.