From a "rules" standpoint, the only key issues are:
Good practice is to have your dive computers in your carry on where they are less likely to activate and common sense would be to take mission critical/custom/expensive/delicate items in your carry on to the extent possible. Whatever you would most want to have if your checked bags were misrouted, lost or abused.
If you have a camera housing, remove the o-ring or port so that you don't end up having the thing locked up tight because of a pressure difference. It needs to breath. Same with a gopro housing - leave it open. Otherwise, it can burp air out when the pressure is low (not designed to contain air) and then be a bear to open once you're back on the ground.
(1) lithium based batteries must be carried on and it is good practice to "safe" them by removing them from lights and having a little case for them. Those usually cannot be checked because of the fire hazard. If you have a big canister light, you might want to print out the specs and the rules about how big the battery can be so you can show the TSA that it is compliant. see Air Travel with Lithium
(2) don't carry on tools, not just cutting devices. It's mostly been a problem internationally, but I've had scuba multitools (without blades), even tiny crescent wrenches, and cable wraps confiscated when I happened to have a save a dive kit in my carry on. I guess they theory is I might have disassembled the plane from the inside out and used the little cable ties to handcuff infants.
(2) don't carry on tools, not just cutting devices. It's mostly been a problem internationally, but I've had scuba multitools (without blades), even tiny crescent wrenches, and cable wraps confiscated when I happened to have a save a dive kit in my carry on. I guess they theory is I might have disassembled the plane from the inside out and used the little cable ties to handcuff infants.
Good practice is to have your dive computers in your carry on where they are less likely to activate and common sense would be to take mission critical/custom/expensive/delicate items in your carry on to the extent possible. Whatever you would most want to have if your checked bags were misrouted, lost or abused.
If you have a camera housing, remove the o-ring or port so that you don't end up having the thing locked up tight because of a pressure difference. It needs to breath. Same with a gopro housing - leave it open. Otherwise, it can burp air out when the pressure is low (not designed to contain air) and then be a bear to open once you're back on the ground.