Thanks and if you have the trusty Vault 13 Canteen from the Classic Pack, does it make a difference at all?
I bought from Steam, so I had the Caravan pack, no canteen. I think it just lets you fill it up with water when you are near a source of running water.
IMO, when playing vanilla hardcoe (without any mods), water and food are simply too abundant in the game and you only need to sleep a couple hours every 7 or 8 days, so it's kind of interesting, but quickly becomes pointless, other than the ammo weight and the fact that you don't instantly heal from stimpaks (which is a huge improvement over non-hardcoe mode).
It wasn't until I installed the Harder hardcoe Rates mod that I really began to enjoy the hardcoe mode, because I started actually running out of food and water and suffering massive penalties.