I got frustrated with my continually emptying waterskins, too. I've found that you can run a short distance NE to Nardah, buy a bowl from the general store, and refill everything from the fountain there (if you've completed the quest.) Hope this helps! Buckets are faster. A bowl fills a waterskin to 3, a bucket to 4. More buckets are better, because you only have to click once on the fountain to fill them all. If you cant use the fountain because you didn't do the quest, just store lots of buckets filled with water in your bank before you go to the desert. When your waterskins are empty, go to bank and fill them (just keep clicking with the last bucket with water in your inventory on the last waterskin in your inventory). Dont carry buckets (or bowls) with water in the desert, because you drink the water from your bucket before you use your waterskins (even if you have it last in your inventory). When you drink from a bucket (or bowl), the bucket is empty after only one drink.