I'm looking at strain gauges but I'm not sure that would work for this application. I'm trying to figure out how to make a device that would measure wind speed and possibly direction right at the surface of the sail on a sailboat. I'm not referring to the ambient wind around the sailboat but that air which is moving across the sailcloth.
Sails are generally more efficient with nice laminar flow over the sail and less efficient if the air is turbulent. I'm thinking I could make a device to measure these conditions and infer from there efficiency.