How do deal with sharp fins

[NoobinPeru]

I recently acquired my first shortboard and find myself facing a bit of a dilemna. Funny enough, transitioning from the longboard and riding the shortboard is not the problem--on that I've done quite well. My problem is the razor sharp fins that keep cutting the back of my heels. I realize my body position on the board when this happens (moving from sitting way back on the board to prone) so I can avoid most contact, but not all. What is the common resolution for this problem. Is it ok to sand down the edge of the fins a little bit? These fins are definitely sharper than those on my longboard.

[Naughtydoggballa]

not really sure what you mean with the positioning thing but good fins are supposed to be sharp with certain thickness in the center so it gets push but there is not much drag for things like turns, snaps, cutbacks, and even in the barrel; but if your just starting shortboarding i'd recommend buying protec's which are fins with a rubberized like tip so it just hurts instead of lacerating and another tip that I learned the hard way if you can't duckdive a certain wave be careful diving under with your board away from you I recently kick my fin so hard it opened it to the bone because I was surfing shorebreak that was overhead and there was no way of duckdiving it was so shallow so I had to dive into the wave each time, well one wave I dove and kicked and my board was too close so watch out for that, but besides that I would definitely look into the protec's because you need some time to get used to your legs hanging off the back and shortboard duckdiving no need getting injured where you can't surf.