They've had sailing in the Olympic Summer Games since 1896, but the number of divisions and the types of boats have changed a lot, as interestingly described in this Wikipedia article. Right now they race about 7 types of boats, which includes one type of windsurf. In this post I briefly describe all the current Olympic classes, then weigh in on the controversy of whether things should be rearranged to add kiteboarding as an additional class.
The longest enduring model of boat in the Olympics is the "Star", a 22' keelboat with a crew of two, which was designed in 1910 and has been in the games since 1932.
The second longest enduring Olympic sailing class is the "Finn", a 15' dinghy sailed by one person, which was designed in 1949 and has been in the games since 1952. Compared to other singlehanded dinghys, the Finn favors a bigger, heavier sailor, so the burly male sailors of the world insist that the Finn remain an Olympic class to give them a chance to compete at the top level.
The third oldest Olympic Class is is the "470", a high-performance 15' dingy sailed by two lightweight athletes. It was designed in 1963 and has been in the games since 1976. The 470 is really complicated, with a lot of sail area divided among three sails, and a "trapeze" so the sailors can hike out over the water to balance. It requires a bunch of weird physical techniques from the sailors, like pelvic thrusts and disco pointing, to reach maximum planing performance. Fabulous!
Since 2000 there has been an even more complicated and higher performance 2-person dinghy in the Olympics. It's called the "49er". These boats have a ridiculous amount of sail area and special wings that the sailors stand on to get leverage over all that power. 49ers are fast enough to be competitive with windsurfs and kiteboards.
There's two other kinds of dinghy in the Olympics, the Laser (for men), and the Laser Radial (with a slightly smaller sail, for women). The lasers are nice, cheap, simple boats with one sail that are very popular with recreational sailors. The laser is a singlehanded event in the Olympics, but it can hold two people if they're not too heavy.
There was a 20' catamaran called the "Tornado" in the Olympics from 1976 to 2008. They dropped it for 2012 but they're probably going to bring it back in 2016. It has a two person crew.
The newest Olympic boat is the Elliot 6m, a moderate-sized keelboat with a full array of sails and a crew of about 3. It was designed around 2000 and will sail its first Olympics in 2012 as a women-only event.
Last but not least is the windsurfing class, which has been in the Olympics since 1984. In '84 the board was a "Windglider", which was a flat-bottomed longboard similar to the original Windsurfer One-Design that popularized the sport in the 1970s. In '88 they used round-bottomed boards called Division II boards, which were fast in light winds but awkward to sail. They used round-bottomed boards again in '92, but with some upgrades to the board and sail. From '96 - '04 they used a modern, flat-bottomed longboard called the Mistral One Design. That was a good board, but people complained that you had to be a very specific weight to be competitive. They also complained that the narrow longboard wasn't representative of performance windsurf racing in the 2000s, which was mostly done in 100% planing conditions on wide shortboards. In 2008 they changed the Olympic windsurf board to the "RS:X", a cross between a longboard and a wide shortboard, which used a daggerboard in light winds but fully planed around the course without the daggerboard in stronger winds. (For more info on the different kinds of windsurf racing, and picture, check my older blog post here.)
The perennial crisis for Olympic sailing comes from the fact that hardly anybody cares about sailing except sailors, and sailors care SO MUCH about their own favorite types of sailing that they rarely see eye to eye regarding what types should be in the Olympics. That and there's a high cost and hassle per athlete in sailing because of the large and expensive equipment and the logistical support needed. With those challenges in mind, I think that the organizing principles for choosing Olympic sailing classes should be:
1) Representing the most popular, affordable, and portable type(s) of sailing with the minimum number of classes.
2) Providing an interesting spectacle for TV viewers, raising the worldwide profile and popularity of sailing sports.
3) Giving a fair chance for the most talented and dedicated athletes to rise to the top.
For #1, I think it's useful to start by supposing you can only have ONE kind of sailing in the Olympics, so you have to pick the most general. Then as you add additional classes you do so in the way that hits the broadest branches of the sport first and the finer divisions later if resources allow. If there could only be one kind of boat in the Olympics I would pick a simple, single-handed dinghy like the Laser, which has all the elements of a traditional sailboat, including a fixed mast, a centerboard / keel, and a movable rudder.
If there could only be two kinds of boat, I would pick Laser and kiteboard, because kiting is the most different kind of sailing from the Laser, yet it still meets the criteria of being popular, affordable and portable. As a bonus, kiting would be a good TV spectacle (#2 on my "organizing principles" list).
If there could be three kinds of boat, I think windsurfer would be the next to include. Windsurfing is not as distinct from traditional sailing as is kiting, but it's still pretty different, seeing as the sailor stands up and holds the sail and doesn't use a rudder. Windsurfing is also pretty good as a TV spectacle because of the speed and the focus on the athletic rider.
If there could be four kinds of boat, I would add a sporty, 2-person catamaran. Little catamarans are the cheapest and most popular kind of high-performance sailboat, their split hulls effectively differentiate them from the first four kinds of boat, and they look pretty dramatic on TV when they get up on one hull. The Tornado catamaran that they've been using lately seems like a good one.
If there could be five kinds of boat, I would add a moderate-sized keelboat with a crew of about 3, since a lot of the world's recreational sailboat racing is done on boats of similar nature, i.e. bigger than a dinghy. Having a "real" sailboat in the Olympics might also help evoke the nautical mystique and the seafaring and naval battles of yore. As for the particular boat model, I think the Star has had a good run, but it's an old design that's boring compared to modern keelboats of similar size like the Elliot 6m. So I'd vote for the latter or something like it.
Only if there could be six or more kinds of sailboat would I consider adding a high-performance dinghy (aka "skiff") like the 470 or the 49'er. If it came to a choice between the two, I would go for the 49'er, because if you're going to go high performance you might as well go all the way for the maximum TV spectacle, and also because the 49'er is supposedly more accommodating of different size and weight sailors.
I'm getting pretty long-winded here, but I can't skip #3: giving a fair chance to the athletes. Making the competition fair for more than one specific body weight has been a major point of contention. One solution might be splitting the classes into actual body weight divisions by rule instead of de-facto body weight divisions by class of boat. Then you could get rid of some of the cheesy classes of boat like the Finn that only exist for the heavier sailors. Having fewer classes of boat, but more competitors per nation per class of boat, would give the competitors more opportunities to train together and share equipment and stuff.
For windsurfing and kiteboarding, fairness could also be increased by relaxing the one-design restrictions to allow different sized sails or kites for different weight competitors. That seems to work pretty well in the Kona ONE windsurfing class. You could also go a step further by allowing windsurfing and kiting competitors to choose different equipment for different conditions under a "box-rule". A box-rule allows a diversity of gear, but sets certain limits on the amount of stuff each competitor can bring, what size it can be, whether or not it can be custom made or has to come "off the shelf", etc. For example, the box-rule for the formula windsurfing class says you can bring one board with a max width of 100 cm, three sails with a max size of 12.5 m^2, and three fins with a max length of 70 cm. Switching gear between races would require a shift in the way the competitions are held, but you would need a shift, anyway, if you were going to try to accommodate kiting. That is, instead of launching from a marina or boat ramp like the current Olympic classes, the kiters would have to stage their show from a beach, and the beach would suit the windsurfs better, too.
I think some kind of blend between a box-rule and a one-design rule would give the best combination of fairness, coolness, and affordability for Olympic windsurfing and kiting. Like, multiple sizes of sails and kites would be allowed, but they would all be the same model, and there would just be one model of board. Being allowed to use a jumbo kite or sail in light wind would make 100% planing competition realistic in winds down to 7 or 8 knots. And the windsurfing class could finally get away from the continuous sail pumping, aka "air-rowing", that characterizes underpowered windsurf racing. Air rowing is an extremely athletic skill, and I have the greatest respect for those who are good at it, but it looks super lame and unappealing and windsurfers rarely do it except in Olympic style competition.
One problem with getting a tight box-rule for kiteboarding (which I believe is a prerequisite for fair Olympic competition) is that most kite raceboards have at least three fins, with an infinite variety of fin sizes, shapes, and tilt angles that need to be tweaked and changed all the time for different conditions.
A possible way around that would be to use a twin-tip kiteboard with a single center fin that could be adjusted on the fly for different conditions. This kind of board is a recent development, but it apparently performs on about the same level as the more fin-crazy directional raceboards.
Whew. I should stop there.