Schaefer Great Hawk Wind Indicator f/Boats From 8M - 20M15" Great Hawk For boats from 8m to 20m The Great Hawk is designed for Cruising and Racing yachts up to 20m. The Great Hawk vane arm is made from the same super tough nylon and the Reference Arms are made from glassed filled nylon for ultimate rigidity and UV protection. The precision balanced vane arm and Hawks "V" Jewel bearing surface gives instant response to shifts and gusts with minimal inertia. The Reference Arms may be preset at 55, 60 or 65