RE: free ride fin for 85L
Ummmm... quite a dilemma you have going here.
You 85 L JP has an "A" or "E" box fin, right?
That's going to be very hard to change, out in deep water.
So, I think you will need to get an improved or larger free ride
fin that works on your board for the "out there" B&J conditions.
But, this isn't going to be the "magic solution" that you seek as it sounds like you are slogging (not planing) for that first 1 Km off the beach.
Unfortunately, there isn't any kind of fin that's going to really make much difference on an 85 liter wave board with soft rails in sub planing conditions.
So, while you are in Hatteras, you can try some different (larger or more area) fins, and I'm sure they will improve your upwind capability
when planing, but won't do much for you when slogging.
If you get a fin big enough to make a difference, then it's going to be way too big once you get out to the windline and B&J conditions.
Sorry, I think an upgraded fin may help a little, but you'll still have to stand the little wave board on the upwind rail and slog out there.
The only thing you can do in "slogging" conditions is use the shape in the bottom of the board to stay upwind and go very slowly.
Hope this helps,