Bonaire is geat
As Ellen says Bonaire is wonderful for improving your windsurfing skills. I'm an intermediate 57 old and have gone the last 4 winters. I really like it and stayed 5 weeks this year.
I book through Ann Phelan and stay at Coco Palm Gardens which is 5 miles from the windsurfing centers. You might want to take some lessons and the 5 lesson package is a good deal at Jibe City.
I would suggest going for a couple of weeks the first time to see if you like it and then you can stay longer next time.