HI,
I just got back from a 4 night trip so I'm a bit late on a response here.
I think Rick really had the correct information.
And as far as United, Hm I'm not surprised. Although I recently took my equipment on a ATA flight and they were more amazed at the reg, then anything, in security, and didn't mind at all.
Most of my group dive trips are split 50/50 on this one.
Some like to pack everything in thier regular luggage, and not in dive marked bags,and check it all, and some must carry on their reg and computer, and camera.
I have done it both ways. I have carried the reg, I have packed the reg, it has always arrived without a problem. The cabin pressure is the same, like Rick stated.
I always carry on my camera. I just have to be sure I have underwater pics. I use a dive watch and I wear it.
I just always say a prayer over everything I hand over to them. And I mark my bags with bright colored yarn and give the same yarn to everyone in the group. I think this way, if one bag is sitting by itself on the tarmac, maybe the baggage handlers will realize it has the same yarn as all the other bags, and belongs on this flight.
Hope I helped, without getting off the subject.
:sunny: