*FIN ULCERS- If you are getting blisters from your fins, the first step is:
Prevention: Dab huge globs of Vaseline on areas inside your fin where you feel blisters might start. This is especially effective with a new pair of fins. It will lubricate these areas before blisters start while you're breaking in the new fins. Alternately, you can pick up a pair of fin socks in our accessories section.

Treatment: If you've already got sores from the fins, try buying those corn or bunion cushions (see picture above) at the drug store/chemist. They're shaped like donuts. Stick one over your sore with the sore in the middle open part of the cushion. For reinforcement, you can lay duct tape over that to keep in on, and that should protect your cut from getting worse.