Boost fuel efficiency and get on a plane faster with Stingray XR III Hydrofoils.Stingray XR III Hydrofoils help outboard and sterndrive equipped boats to plane faster, eliminate chinewalking and porpoising and improve stability and fuel efficiency. What makes these hydrofoils super-efficient is SPEED-XP—an extreme performance hydrophilic material that increases the speed that can be achieved over previous models. SPEED-XP binds a thin layer of water to the foil, dramatically reducing hydrodynamic drag and improving overall performance. Unlike simple curved or flat planing aids, these hydrofoils actuall create lift so your boat gets on to a plane faster. This benefits waterskiers, powerboat racers and others looking for quicker acceleration and improves safety by keeping the bow down, which improves your field of vision.StingRay XR III SelectionStingRay XR III hydrofoils are offered in Junior and Senior sizes. The Senior models are designed for motors 75 HP and up. In most cases, Junior models are for boats under 75 HP. When selecting, the weight of the boat and motor should also be considered. Heavy boats at the lower end of the HP range will benefit from the the Senior model depending on much lift they need. The only limiting factor is the width of the cavitation plate. Senior models only fit up to 7" wide cavitation plates. Junior models fit up to 5" wide cavitation plates. These hydrofoils are easy to install with no drilling required. Packaging includes instructions and all necessary hardware.Key FeaturesGet on a plane fasterBoost fuel efficiencyEliminate chine walking and porpoisingImprove stabilityReduce dragImprove field of visionSelection GuidelinesUnder 75 HP: StingRay III JuniorOver 75HP: StingRay III SeniorIn some cases, heavy boats under 75 HP can use the Senior model, depending on how much lift is required. See limiting factors above