For many years, I would see a small ad in the New Yorker Magazine for a "Greek Fisherman's Cap". I always wondered who bought these caps in the US. Now many years later, just for the fun of it, I searched for "Greek Fisherman's Cap" on the net and lo and behold a mass of images appeared. That cap is popular. And there are a lot of places to get them too. Here and here and here. So there!