With carry on space being premium, I only take my camera and lenses with me.
Everything else goes in a locked Pelican 1610 case, never had any problems.
Both mine and wife's diving equipment goes on another big Pelican we just call "The Frigobar", even our computers and regs. So she has another suitcase for her and I have another one for her shoes...
UWPhoto (housings, ports, strobes, arms, cables...) equipment is not fragile, it requires care, but it is not fragile. Something that protects your camera at 60m down cannot be fragile.