T-Rex Ferociously Strong Waterproof Tape provides tough waterproof adhesion under wet and dry conditions. Built with R-Flex Technology, T-Rex Waterproof Tape can stretch up to 700% of its original length. It’s strong enough to be used for general purpose indoor or outdoor fixes that require a waterproof seal, like repairing a rip in an above-ground pool or temporarily stopping a leak in a water pipe. Or apply it underwater and push it into cracks and rough, dirty surfaces. T-Rex Waterproof Tape. Flexible, ferociously strong and waterproof like no other.