It's an old argument, but in eight years and over a thousand dives, I have yet to want a snorkel WHILE DIVING. I've been on the surface in ugly chop and big swells, and still didn't want a snorkel. I can think of two times I would have liked to have had one -- once surface swimming in Hawaii, when we had a huge turtle go underneath us, and the other when riding back to the ship on the RIB in the Red Sea, when we ended up in a pod of about 30 dolphins. Other than that? Nah.