Definition: Fins are long flat rubber or plastic extensions of your feet that allow you to swim with much greater ease and speed. The two primary varieties of fins are full-foot and open-heeled. Full-foot fins completely cover the foot like a shoe and are most commonly used in warm tropical water. Open-heeled fins have a strap across the back and are worn with booties to allow the feet more warmth and comfort.
Also Known As: Flippers