Truefin is 100% nonmetallic in order to ensure rust and/or corrosion can never be an issue in fresh or salt water. The bottom of the foot pocket is reinforced with an overmolded substrate chassis and is relatively rigid. Upper surface of foot pocket is not over molded, and is highly flexible and tapered thin (down to 0.140”) to the center top edge which improves comfort and reduces concentrated forces at the top of the user's foot. The foot pocket includes toe vent holes in order to minimize parachuting while moving through the water and also to minimize suction and allow drainage while facilitating removal of the fin from the user's foot. The external sole or power plate of the fin includes relatively complex geometry of a low profile non-slip design to both maximize traction while wearing the fin out of water, yet minimize turbulence or drag forces while finning in water.