Knowing this topic has been discussed already I still want to show how I do with my rig since I got recently a storm roller bag, in which I store the housing (Subal for S2 pro), the Subal Dome port for the 12-24 lens, a Nikonos SB-105 Flash and a Sealux Flash housing for Nikon SB-80DX and some accessories. The storm case is supposed as a carry-on. All my camera gear goes into a small Tamrac photobag. The Tamrac photobag can be attached onto the handle of the storm rollerbag and is also for carry-on. The Subal port for the 70-180 microzoom goes in a small pellicase, which goes into my divebag (to be checked) together with the arms for the flashguns and the other dive gear.
I have not yet travelled like this but will go to the red sea soon. In earlier trips I used another big Tamrac photobag in which I stuffed everything into as carry-on, but with a heavy weigtht of around 30 kg I almost broke my shoulders! So this way with the wheels on I should be better of assuming that the airline does not require me to check it.
Any comments or suggestions are welcome.
BTW, I got so many useful and interesting hints from this forum that without it I would have been lost in setting up the gear. Thank you all!
I have tried many different methods of traveling with underwater dSLR gear and have found the best to be using the largest carry on suitcase the airlines allow with separators from another camera bag (packed tight). The obvious disadvantage is lack of protection with the soft bag but since I carry it with me there is no worry of baggage handlers. The other advantage is it has wheels.