Hood River used to be the best and perhaps the only great windsurfing spot in the north-western U.S. It still is probably the best place for families, novices working on their waterstarts and jibes, and for people who just come to watch.
This is the best feature of Hood. Launching takes place out of a shallow cove that is protected by jetties on both sides. The water is very smooth for the first hundred meters or so.
Usually the wind is in the 5.0 to 6.0 range and gets stronger the further out you go. Best time is in the summer mornings. The swell is around 1 to 3 feet high but on big days it can get mighty big. The thing to remember is that Hood River is a river. The current gets stronger on the outside. If you find yourself drifting downstream, just put your feet down and you'll probably catch the sandbar formed by Hood River entering the Columbia.