I have the original 69 wood board that has been epoxied, faired, gelcoated as needed. Its a pretty tight fit in the slot. Yesterday I put two vertical Velcro soft sided strips on each side...for and aft. Board still slide in ok but was a little tighter. Still hummed like a bad boy.
Well...gonna fair it out more hydrodynamically when there's time as a last resort before a new glass one. Oh well....it's only $$$ on this free fish. :-/
Mine used to hum, and I was fine with it. But then it started just humming "it's a small world after all" from Disney World. That was driving me nuts so then I fixed it to stop humming.
Don't run a sharp trailing edge. Take a sanding block and sand the trailing edge 1/8" thick with a 20 degree taper by sanding that side more. It will not hum after that. so the back will be I/ as opposed to V