A recent discussion on the Duckworks mailing list taught me a couple of little tricks that I thought were worth sharing.
If you have tie-down straps (say holding your small craft on your car top) that are vibrating in the wind, there is a solution: twist the strap several times so that it is not flat.
I know that newer car radio antennas often have a spiral "ridge" on them that supposedly helps with sound and vibration. This tip seems to follow the same idea. I’m sure there are some very fancy fluid flow dynamics involved, but seems like its at least worth a try.
Varying recommendations on how many twists came up. It depends on the strap width, length of unsupported span, and speed, so just give it a try. One person even suggested twisting it many times until its more round than flat. I’m not sure if that is going to have adverse impacts on the tie-down aspects of the strap, but I imagine it certainly changes the vibration properties.
One last tip… if all else fails, get some of the round foam pipe insulation and tape it over the strap… apparently that works also.