Sometime in 1967 Jim Drake, a sailor and aeronautical engineer from Southern California, and Hoyle Schweitzer, a surfer, also from Southern California, posed the question: "What do you get if you cross a surfboard with a sailboat?"

The answer, we now know, is windsurfing. But what's obvious now wasn't so obvious then. Although Drake and Schweitzer had their patent by 1968, it wasn't until the early 1970s, when windsurfers reached the shores of Europe, that the sport began to get noticed.

Windsurfing is still not real popular in the United States, but with an estimated 1.5 million participants and over 500,000 boards in use here, it is fast becoming one of the more popular pastimes. On almost any weekend morning at any one of the local marinas that offers public access to a beach or launch, there are windsurfers just off the shoreline.

Amid a flotilla of neon pink, yellow, and purple sails, brightly patterned boards and the chatter of jargon like "duck" and "carve gybes," "uphauling," "fast tacks," "reaching" and "running," the sport just plain sounds like fun. For Myrna Sislen, a classical guitarist and an avid windsurfer for four years, it looked so enchanting she just had to try it. "I watched for about a year," she said. "I'd drive by the water and see them out there and it looked so pretty. But it wasn't until I got a job at Club Med one year that I actually tried it."

As you might imagine, the main topic of conversation among windsurfers is wind: the time it blew too hard, the time it didn't blow at all, the time it left them stranded. Everyone has a story to tell.

There is one inherent characteristic all windsurfers possess -- tenacity: that willingness and stubborness to endure a tremendous amount of aches, pains and humiliation. Every windsurfer has to learn the hard way. Everyone falls, everyone gets tired and, above all, everyone gets frustrated. Yet, for the thrill of gliding through the water with only the wind at your back, they endure.

Proper instruction from a windsurfing school makes learning easier. An eight-hour certification program of instruction costs $90-$100. Most board rental facilities require a certification card before you can rent a board.

Most lessons begin with on-land simulation: a board mounted on a turntable that allows it to pivot freely and lets the student to learn basic skills such as getting on the board (not as easy as it sounds), uphauling the sail and turning the board.

Some lessons move from the simulator to a tethered board exercise, done on a board anchored in the water. This allows the student to learn the feel of the board and the wind without the fear of being blown out to sea. Those that don't include this exercise at least provide closely supervised instruction in a protected area of water.

If you were confident on the simulator, beware. The feel of the board on the water and the wind in the sail is completely different. You will fall -- a lot. You will fall on top of the sail and the sail will fall on top of you. Your knees will be skinned from continuously mounting the board and your hands will be sore from uphauling the sail.

Eventually, though, things start to make sense and all of the basic skills start to fall into place. Along with basic boardsailing techniques, a school should offer some instruction on wind theory, basic water safety and seamanship, and water courtesy.

If you think you'll get bored going back and forth across the water a few times, think again. Advanced technology has made available varieties of boards and sails that provide many opportunities for the boardsailing enthusiast. Some like regatta sailing and others like speed racing. Some prefer the thrill of wave jumping and still others like the creative expression of free-style maneuvers. Because the sport relies on balance and finesse, not brute strength, it is something that can be enjoyed at any age.

The Washington Boardsailing Club can provide more information on instruction, regattas and competitions both locally and nationally. They also have information on launch areas, board rentals and sales. Contact Ian Jones, WBC president, at 759-3002. A local windsurfing retailer also should be able to provide this information. For instruction, call Bob Redmond at the Washington Sailing Marina (548-9027) or the Belle Haven Marina (768-0018).