In one sentence, describe what the following article is about:

The point of any swimming unit is to learn how to swim (or to improve in your swimming skills), and you won’t get much out of the class if you don’t participate and make an effort. Whether this is your first time in the pool or you’re an experienced swimmer, get out there, participate, and have fun! Even if you can’t swim, try your best. Most teachers can recognize when someone is trying and will give you a good grade for effort. High school swim unit is a great opportunity to improve your swimming skills, especially if you plan to compete in a swim club. Your swim coach is most likely a highly qualified individual who cares about his or her students and wants to help them swim better. Even if you’re not a competitive swimmer and have no plans to become one, you should still obey the coach. He or she can lend a fun sense of community to the class, and swimming is a great way to stay in shape. Many high-school students are already involved in a swim team, and regularly compete in swimming or diving competitions. Learning from a coach is especially valuable if you’re already a competitive swimmer. Even if you routinely swim and train at a private swimming club, your high school coach can add a sense of community and team spirit to your swimming. Focus on learning new strokes and improving your time; tune out distractions. Take your training—even if it’s not at your normal swim club—as seriously as possible.

Summary:
Try your best in the pool. Listen to the coach and follow their direction. Improve your competitive swimming abilities.