Known for supplying windsocks for aerospace and industrial applications, Airport Windsock Corporation has developed a windsock specifically designed for the harsh marine environment. Wind contributes more to the challenge of docking than all of the many other factors combined.
Along with giving an accurate wind direction at wind speeds as low as 2 mph, they are calibrated to fully extend at 15 knots of wind speed. This wind speed indication gives the boater wind speed reference before approaching the dock. With its all stainless steel windsock frame and a UV protected windsock, these units come screen printed with "No Wake" on each side. Other images are available such as "no wake zone", "idle speed no wake" or "slow speed no wake" at no additional charge. They are also available with your marina's logo or name for slightly more.
(www.airportwindsocks.com)