Odds of Getting In
In the summer, there's plenty of work, as long as you don't mind the low wages. Swimming schools, YMCAs, summer camps, and community pools all see an upswing in enrollment for swim lessons over the summer.
If you're certified and have all of your Red Cross CPR certifications in order, you should be able to find work somewhere. It's common to secure a role as a lifeguard who gives swim lessons as part of the package.
If you're thinking of starting your own business, there's plenty of customers (especially during the summer). The competition is fierce but if you have business savvy and great teaching skills, you can come up with a marketing plan that makes a go of it. Word of mouth travels fast.