As anyone who has been in a sailboat or forgotten their jacket can tell you, air may be thin but it can still transfer a lot of energy. Because wind will move seasteads around, batter them during storms, and help them generate electricity, it is an important part of our ocean environment. There are basically two kinds of winds we need to worry about, the good kind which blow slowly and steadily, and the bad kind which swoop in occasionally and try to steal anything which isn't nailed down.