Check Craigslist. People nearly giving gear away that's in decent shape if you wait to find it. If you've got a vehicle or racks that can transport something as big or slightly bigger than a bigger SUP, you'll have no issue. I'm getting to this when I find the time because when it's flat there's still wind and this is a different yet supplemental workout to what we are doing.
I windsurfed for several years in the early 80's while in the Navy and for awhile after I got out. Never used it out in the open ocean - only bays and such in Pensacola, San Diego and a few other places in SoCal. For some reason, the popularity seemed to have declined after the 90s. Not sure why. I don't see them around as much anymore. Mostly kite surfing now. Also, it was dropped as an Olympic event. But there are active Windsurfing groups out there. It would be a fun alternative on those flat, summer days.
After not using my rig for years, I finally sold it cheap. Wanted someone to get some use out of it before it deteriorated. I had bought the basic model for about $700 in 1981 while stationed in Pensacola.
I strongly recommend taking some initial lessons instead of trying to teach yourself.
Windsurfing has a pretty steep learning curve--it really helps to have a good base of sailing knowledge before you attempt it. I taught windsurfing occasionally back when I was a sailing instructor and had access to a wide range of equipment I could use whenever I wanted--the guy who owned the shop I worked for was a pro windsurfer and sailor (trying to find a photo of him doing a backflip off a 3' wave in WB in the 80's.. but can't locate it).
Anyway, DO NOT GET A SMALL BOARD AND DO NOT GET A LARGE SAIL AS A BEGINNER. You need to start on a large board, a sail smaller than 4m, go out in less than 10 knts and work your way up from there. You should be able to walk all over the board without sinking it. Most people accustomed to board sports think you turn a windsurfer like you do a surfboard because they see the pros doing something similar on tiny high performance boards.... That's not how it works--you use the sail to steer. Don't even worry about attempting to sail a high performance windsurfer with a "real" sail for a long, long time... unless you want to get discouraged quickly. Take some lessons.
And to set the record straight: There is almost no crossover in technique or muscle usage between surfing and windsurfing other than standing with bent knees. Kiteboarding is much closer in similarity from a crossover workout perspective, but it's only similar in the lower body. Both will do absolutely nothing for your surfing balance and can mess it up (like wakeboarding too as I have been guilty of in the past).
Bottom line: Windsurfing is great fun! Just go out there with the Cruiser mindset, not the Shred The Gnar mindset and you'll have a lot of fun and get a good base to progress from (if that's what you're after). I would still do it if I had all the time in the world to do all the fun water sports I've enjoyed at points in my life.
+1 on everything Erock said.I use to teach windsurfing at a resort that i worked at and the biggest mistake you can make is getting a small board and big sail..Try to learn about sailing and wind direction too..
Never tried either windsurfing or kitesurfing, but I have to ask, why would you want to learn to windsurf when you could learn to kitesurf? It just seems like there's so much more room to do crazy tricks/adapt it for surfing/have a helluva lot more fun...Isn't that why no one windsurfs anymore? Because kitesurfing is way more fun?
I don't know but that's just my feeling. I LOVE flying kites (as lame as that sounds) and my goal is to be kitesurfing within the next year. Time and money are the only little obstacles in my way.
Just thought I'd offer up my opinion and see how other people feel...maybe people that have tried both could chime in?