The Marines customized their gear to provide greater utility.
For example their field packs and tents are a more modern, modified civilian design. The story goes that the Commandant of the Marines Corps was on a field exercise and got drenched because his tent was a POS, so he ordered a study to find the best equipment.

Also instead of canteens the Marines use a flexible pack with a drinking tube, so you don't even need to get it out of your ruck.