I would use Ding Tape.. or just leave it open.. Are you worried about drag or looks.

If you want removable you can chop an old damaged fin off at the base and use that with a screw and plate .. (even a cheap plastic fin cut at the base)

DJ

I'll try the blind test. Given my low skill level you are probably right. What got me on this thread was that I can notice the fin setup (quad vs 2+1) repeatably.

Also, I come from a yacht racing background and know that on a yacht such a shape would be filled in due to drag.

That said, I will tape it up and go for a surf then remove it and see.

Just a thought I havent tried myself...
Spray inside your finbox with canola cooking spray lay something like a tampon string inside then fill with silicon/ silastic smooth it off with wet finger...when set hopefully pull it in and out with the party popper string as needed

LordRumpunc said...
Tried the tape test this morning. Definitely felt a 0.002% increase in drag without the tape....then I fell off. I should use the tape to keep me on the board.

so much for that idea

You're honestly questioning the drag-coefficient that an 'open' finbox has on your 40 foot long barge?

Surely the surfers, boogers and assorted small children you guys run over on a daily basis would have more of an impact on your straight line speed?

Just saying...

LateStarter said...

LordRumpunc said...
Tried the tape test this morning. Definitely felt a 0.002% increase in drag without the tape....then I fell off. I should use the tape to keep me on the board.

so much for that idea

You're honestly questioning the drag-coefficient that an 'open' finbox has on your 40 foot long barge?

Surely the surfers, boogers and assorted small children you guys run over on a daily basis would have more of an impact on your straight line speed?

Just saying...

Good point.

What type of finish should the surfers, boogers and assorted small children wear so we reduce the impact on our straight line speed when we hit them?

LordRumpunc said...
What type of finish should the surfers, boogers and assorted small children wear so we reduce the impact on our straight line speed when we hit them?

:)

For every surfer trying their hand at SUPing there are umpteen non-surfers who do the same, and herein lies the problem.

These guys haven't spent the time in the water to know the 'rules', to display good surf etiquitte and to operate their craft in a manner that is unlikely to pose a threat to their own safety or that of others.

Granted, there are no shortage of clown on shortboards or sponges either, but you cannot argue that the potential for carnage is greater than that of a runaway SUP.

I think anyone who sells/hires/demos these crafts should have a duty of care to educate their customer, so that we can all enjoy our time in the water.