I just took my mask, snorkel and flippers halfway around the world for six weeks, about 10 planes. I put it in my checked bag, though I think I could have carried it on with no problem.
snorkel
I don't know if snorkel gear can be rented at Hilton Head. I always take my own because often times the gear you rent will be wore out. Good snorkel gear isn't that expensive and it packs well into luggage. Take your own mask and snorkel at least, you will be glad you did. Rent fins would be OK.
When you get to the suface with your head down take a breath off your regulator the take it out of your mouth. Put the snorkel mouth piece in your mouth and blow really hard.
snorkel
a snorkel.
If you are inhaling, not long enough.
3 months, 8days, 2hours, 17mins, 43seconds
Yes, you can take airplane blankets with you on your flight.
A great place to snorkel is in Malta (Europe)
Snorkel
snorkel (it stays the same)
I lost my snorkel; then surfaced.