"Just a thought, Here are some of the makers specs:"
The links don't say much about water resistance.
In the last one, CT says:
"B. Surface Coatings
Film coatings, such as Mylar (a biaxially oriented PET), are used for their high tensile strength, toughness, chemical and dimensional stability, gas barrier properties, high temperature resistance and low coefficient of friction."
No mention of water resistance.