A swim fin includes a foot pocket with a front and rear sections, an upper portion formed of an elastomeric material, a sole, and a foot pocket cavity. The rear section has a rear edge defining the foot pocket cavity. The foot pocket further has an array of through holes disposed through the upper portion adjacent the rear section. The array of through holes is sized and configured to generally increase a surface area of the rear section from the rear edge towards the front section. The swim fin includes a fin blade extending from the front section of the foot pocket. The swim flu may further include an adjustable heel strap. The fin blade may further include side rails attached to the foot pocket with hinges. The fin blade may further include a flex member disposed between first and second body members.