I enjoy swimming. Do you like it?
I love swimming! I can hold my breath for a while too!
Wow, that's pretty cool. How long?
Long enough to free underwater dive below the water's surface for a few minutes. Do you like to snorkel?
I've tried it a few times! I'm afraid of sharks though!
I saw a small shark when I was snorkeling in Hawaii! It was far away though. I love to snorkel. 
I can imagine it's quite nice. Most will probably never harm people too.
It's a good way to get a good look at the fish that live among the coral reefs.