Not a water based product.
Suggest you read their product specifications. I have been using 303 on a 1973 26 ft. sailboat for the past 3 years. I do the topsides with it in April, and it lasts for a year in our climate here on Lake Ontario. The gloss and protection is far better than any wax.This is from their website (link below) - "Does 303 replace Wax on Fiberglass?Gelcoat fiberglass is polyester resin with the pigment in the resin, commonly used in boats, RV’s, snowmobiles, jet ski’s, etc. Gelcoat fiberglass rapidly fades and chalks with traditional maintenance being tedious and repetitive buffing and waxing.303 Aerospace Protectant is an alternative to buffing and waxing. 303 restores like new color and gloss to faded gelcoat fiberglass by spraying on and polishing completely dry.A new appearance is maintained with periodic spray on/wipe off applications usually every 45-60 days of exposure. Fiberglass shines. Colors stay bright.In addition, the 303’d surface is extremely repellent to water, soiling and staining…staying cleaner longer and clean up is much easier when soiled.So for gelcoat fiberglass 303 Aerospace Protectant is a superior with respect to ease of use, level of protection, appearance and repellency."Have a look at their "Recommended By - " page. Pretty impressive I would say.