A good, charitable task you could undertake, potentially for some profit, is to do the CAD design for an O'Fish'l fin box and some fins to fit in there.

Lots of people have boxes already, but need fins in them. I suggest doing the box mainly so you have a test bed for the fins, but a few people have broken their boxes out and need new one, or maybe want a new board compatible with a stash of fins they already have.

Crank out some fins of varying size, sweep, shape, and foil.

Build a small waterflow tank, submerge a GoPro camera, and record the water flow over the fins at 240 fps to compare designs.

You can use strain gauges, or even simple springs, to measure drag and lift of each design.

Make some fins foiled on both sides, and you can extrapolate the results to an airplane wing.