Hi cherinere:
Consider at least carrying on your most important or expensive dive gear. I carry my regulator, computer(s), and prescription mask and check the rest.
I strongly recommend that you not ask the airline for special handling of your checked scuba gear- or even that you mention to them that you have scuba gear. Most US airlines have a policy of charging to carry scuba gear even if it doesn't require special handling. A typical charge for most airlines would be an extra $150+ per diver for a round trip.
If you carry a compressed air cylinder, it is considered "hazardous cargo" by the DOT if it contains more than 40 psi of pressure, so the airline is responsible for making sure that any scuba tanks, pony bottles, Spare Airs, etc. are empty. But other than that, as far as I'm concerned I just put my checked scuba gear in a plain bag and it's none of the airlines' business what's in it.
HTH,
Bill