Yep, I've always been an excellent swimmer. I practically grew up in the water. We had a pool when I was a kid and always had at least 2 boats, so my parents made sure I took lots of swimming classes from the time I could walk. My whole family dives (DH, dad, sis, b-i-l, etc) and I got certified when I was 12. DH and I are counting down the days until DS is old enough to get certified. He loves to snorkel! I also was on swim team in junior high, a synchronized swim team in high school, and I lifeguarded throughout college and was even certified to teach lifeguarding.
I think it's soooo important that every single person knows how to swim well. I started both my kids in swim lessons at a year and make them take lessons each and every summer.