Fin Retainers

[Thalassamania]

I wear them the same way. My boots fit fine and I don't need them to keep my fins on. The only reason I, and most other dry suit divers, wear them is to keep air out of the boots so my feet don't float.

While that shows great ingenuity and is a clearly innovative use, they were designed to go over the fins.

 

[sea nmf]

I put a pair of tennis shoes inside the boot to take up the little bit of extra room. No more slippage. They were small tennis shoes, not the big running/walking shoes.

 

[covediver]

Freediving Fins

Look at the bottom of the page. You can get them online at Bluewater hunter.