Oops! It is early in the morning here. I totally missed the key word "waterproof"....

Are the seams sealed? If not, this or any shelter will leak copiously. This is easily remedied by hand sealing by the owner, preferably before use.

I wonder a little bit about "polyester fabric," since silnylon is so commonly used for these kinds of things. I would think polyester would be strong enough for occasional use.

Excuse me while I go and get some caffeine in my system.