Well, /out/, this has basically turned into picture time since you've answered my question and helped me out.
I will invest in a thicker more solid belt and then put the canteen opposite to the knife, for a bit of balance. I'll probably buy this just to troll people:
http://www.knifecenter.com/item/GB31001771/Gerber-31-001771-Bear-Grylls-Survival-Belt-48-inches-overall>Pic: Black tips shark that was circling us while snorkeling in the middle of the atoll. They're pretty timid though, so there was no real danger. 