Here is a vintage Coleman canvas water bag. Neat piece for your vintage collection! Made from durable canvas, this water bag is designed to hold and transport water. Flat it measures about 26" tall (not including rope) and 13.5" wide. There are a few minor spots on the canvas from storage.
The November 1966 manufacture date makes me think that this "might" have been manufactured for our soldiers in Vietnam? The Coleman brand is known for its quality products.