If he's gonna constantly short tack.
, try this at the pond.
Organise 3-4 crew. and do a roster.
3 of you have fun, while you have a tail gater. ride behind him on the way out, nice and close. When he tacks, scream at him as he does not have right of way coming in. Repeat for 5-10mins and swap guys. It's actually quite fun as eventually you see a strange look on their face, then anger. Eventually they get the message and confront you.
Just mention that your possie will continue to blatantly disregard "others" in the water until "others" stop short tacking and not following the circuit. Wreck thier session and they might have something to consider.