Sailing uses the wind to power the boat's motion. It's not as much by pushing the sail (as is the case when sailing downwind) but by creating forward-pulling lift using airfoil-shaped sails (when sailing across or into the wind). The joy of sailing combines the joy of being on the water, the power you feel in harnessing natural forces, and with the thrill of going fast without significant energy on your part.
Sailing dates back to the ancient Phoenician traders, though the technology of sailboats has improved dramatically over the years. Innovations in the past 50 years include fibreglass hulls, metal masts and booms, synthetic sails, computer controlled laser cut and sewn sails, and computer aided design for boat hulls have made sail boats faster, safer, cheaper, and easier to maintain.
Small sailboats under 20 feet in length come in two main configurations: either single hull or multi-hull (like a catamaran). They typically have one mast, one mainsail (the big one), and a jib (the small triangular at the front, to direct the wind around the mainsail), and sometimes a spinnaker (the large round-shaped one for going downwind). Small boats are designed for a limited number of people to crew, with them either sitting in or around the cockpit (which may be a tightly stretched tarp between the catamaran hulls), or supported from a trapeze rig over the edge of the boat (in high winds). Smaller boats with centreboards include modles like Albacores and Lasers.
In coastal waters and in larger lakes, boats can get larger (with fixed keels), more sophisticated (and much more expensive), and can handle larger numbers of people. Some such boats even have multiple masts, and complex sail configurations. Such larger yachts are suitable for a sailing on open water for significant distances, and provide sleeping, kitchen, communications equipment, even entertainment facilities.
There is one sailing club in the BC Rockies where you can get involved, the Moyie Lake Sailing Club in Cranbrook.
The most popular place for windsurfing in the Alberta Rockies is the shallow but incredibly windy Lac Des Arcs, just east of Canmore. Further north is Abraham Lake, between Saskatchewan Crossing and Rocky Mountain House, and Brule Lake north of Jasper. In BC, Windermere and Columbia Lakes are also popular and have warmer waters than their Alberta brethren. All these lakes are glacier-fed and are cold, so wet suits or dry suits are strongly recommended.