skin diving with a snorkel
"The group spent their morning snorkeling in the clear turquoise waters to spot colorful tropical fish up close."
The act of swimming using a snorkel.
"After relaxing on the beach for hours, we finally went snorkeling to see the colorful fish up close while breathing through our tubes at the surface."
present participle of snorkel
"The divers adjusted their masks before beginning to snorkeling along the coral reef."