My past time is going snorkeling,its the practice of swimming on or through a body of water while equipped with a diving mask, a shaped breathing tube called a snorkel, and usually swimfins.
Oh wow! I always wanted to go snorkeling.
cooler waters, a wetsuit may also be worn.
Is there anything else you have to use, like an oxygen tank?
You'll also need a  diving suit is a garment or device designed to protect a diver from the underwater environment
Oh ok. Do you have to take a special class or training beforehand?
Yeah ,it involves the basis of the two surface disciplines of the underwater sport of finswinning.
Well, I'll definitely have to look into it more. It sounds very interesting.
Interestingly,Snorkeling is also used by scuba divers when on the surface, in underwater sports such as underwater hockey and underwater rugby, and as part of water-based searches 
I often get snorkeling and scuba diving mixed up.