Warren,
After losing a couple of caps, I went to a marine shop and got a short piece of bungee cord that had a flat type clip on each end. Fastened one to the band in back of the cap and the other end to my shirt collar and never lost another cap. Some blew off but they were held by the cord and I just pulled them back on as they were hanging down behind my head.
Our weather has been nothing like any August I have ever seen here so far. But we still have a couple of weeks to go and anything could change quickly.
Ron