Transcription: When choosing fins, whether full-foot fins for use in warm water or open-heeled fins for use with wetsuit boots, it's important to choose a pair that fits well. With full-foot fins, you want a snug fit but comfortable so that they don't cramp or bind. If they're too loose, they'll chafe and cause blisters. Size open-heeled fins with your wetsuit boots on. Although you can adjust these fins Sizing is still important. Your foot should go into the pocket so that the fin comes up to the point where your ankle meets your foot. If the fin's too small, your foot won't go in far enough. A fin that's t ...