Stingray AIRO Hydrofoil 2-Piece Boat Stabilizer The Stingray AIRO Hydrofoil is a versatile, 2-piece hydrofoil capable of fitting engine sizes as small as 4 HP while still benefiting larger engines. This economical hydrofoil can be used with engines found in inflatables, smaller tenders, and jon boats, as well as engines up to 350 HP. Hydrofoils are designed to get boats on plane quicker and keep them on plane at lower speeds. This results in increased stabilization and visibility at lower speeds