It's probably not the suggestion you are looking for, but the Aquanaut 5164 (dual time) would seem a perfect choice for me here -- in terms of travel, water resistance, and also general versatility. And you might even find yourself wearing it daily when you don't travel!
I would have also suggested a Patek Worldtimer, that I think is a great plus in any good collection, but water resistance is way below what you need. Of course, this is as far as Patek goes, since there seems to be room for it, but lots of indie choices would be great as well ;-)