There are various competitive swimming leagues. Whether it's a swimming league for children up to 18 years old, high school teams, collegiate teams, or professional, there's a competitive level for everyone.
There are several types of swimming leagues for children. Usually, there are programs that do lessons as well. When you "graduate" from the swim lessons, you are encouraged to join the team and continue the sport at a more competitive level. Places like the YMCA and some Boys & Girls Clubs of America offer these services. They provide a solid foundation for swim techniques as well as other important factors of swimming such as team building, time management and social responsibility.
These swimming leagues, typically for kids who can swim one lap unassisted through age 18, compete in approximately six to eight "dual" meets per season. These meets are one team versus another, and events range from 25 yards (one lap) for the younger kids, up to 200 yards. They also can compete in any number of "invitationals" throughout the year. These are, as the name might suggest, invite-only, and have qualifying times that one must meet before getting invited. Any event can be competed at these meets.
High schools all over the country, as well as some middle schools (albeit more sporadically placed) have swim teams. Depending on the school's athletic funding, this might take place in the school, if they have the proper facilities, or an off-site pool in town. They can have varsity, junior varsity, or freshman teams. Some teams compete as one large unit.
High school meets are also in "dual" meet format, with one team competing against another school. The distances range from 50 yards to 500 yards, including all four strokes. Usually there are less "invitationals" for high school leagues. However, there is usually a large end-of-season championship meet, where all the teams get together in an "invitational" format.
In general, high school leagues follow the same rules as everyone else, except for a few strange particulars. For example, a swimsuit (or goggles, or a swim cap) cannot have more than one small logo on it, for non-sponsorship reasons. Also, all jewelry must be removed before entering the water, including earrings. If they are not removed, the swimmer can be disqualified.
College leagues operate a little differently than what we've seen so far. There are three different leagues that operate within the National Collegiate Athletic Association (NCAA). They are:
Division I athletics within the NCAA are the most rigorous of the teams. Fittingly, they also have the most money for athletic scholarships. They must offer at least 14 sports (either seven for men and women, or six for men and eight for women). There are 335 members in Division I of the NCAA. One-third of Division I schools are private institutions and the other two-thirds are public institutions.
Division II athletics in the NCAA serves as the in-between of Divisions I and III. They have athletic scholarships to offer to their students, but they are rarely full-coverage scholarships. They must offer ten sports. A big part of the Division II philosophy is regionalization, which makes competition localized and easier to access. It also guarantees a more evenly-spread representation in the national competitions. There are about 300 registered institutions that compete at the Division II level, and it's split about 50/50 public-private institutions.
Division III athletics typically are considered the least competitive college division because they offer no scholarship money. It is the NCAA's largest division, comprised of 442 members. Of those members, 81 percent of the institutions are public schools, with the remaining 19 percent private schools. They offer 14 competitive sports and compete nationally.
It should also be noted that a swimmer is only eligible to compete on a collegiate level if he or she has not accepted sponsors. Recently, 16-year-old Missy Franklin has admitted that she's had to turn down sponsors to stay collegiately eligible.
According to USA Swimming, statistically, just .02 percent of registered US Swimmers will compete in the Olympic Games. However, that's no reason to be discouraged. For the 2012 Olympic Games, the top six swimmers in the 100 and 200-meter freestyles will compete in London. In every other event, the top two swimmers to qualify will compete. There will be 26 men and 26 women competing for Team USA.
To be considered a professional in the sport, generally sponsorships are the answer. And to get sponsors, you've got to be the best. In a non-Olympic year, there are World Championship events and other swim meets to get corporate sponsors.