Waterpoofing a boat cover

[GeoFisher]

Cabelas has a roll on gallon of stuff for this exact purpose....about 30 bucks....I have not tried it but plan to next spring...

[jcclark]

the tent spray works pretty good, some Wal-Marts
have it, look in the camping supplies dept.
comes in a spray can.

[zx150]

Aqua tight it is a bit pricey but works great. Put it in a pump sprayer and have at it.

[Carter1]

I have used the spray I got in sporting goods section at Walmart for boat covers, tents and rain gear. It works great.