Determine where the water is leaking from by applying pressure to the vinyl with your hands. Start by cleaning up any water from the mattress with a towel. Check to see if it's located in the seam or body of the mattress. Seam leaks are considered defects, and should be directed to the manufacturer.
Draw a circle around the leak. Place a pillow or book under the safety liner in the area of the leak. This will lift the puncture above water level and stop the water from leaking.
Dry the area around the puncture with a towel. Remove any residue and body oil with a little acetone nail polish remover or rubbing alcohol. Make sure the vinyl is dry and clean.
Trim the vinyl patch from your kit. Make sure the patch is slightly larger than the leak to ensure full coverage.
Spread the repair glue over the puncture area with your finger or a spatula. Make sure the coverage is slightly larger than the patch that you cut. Press the vinyl patch over the punctured area and allow it to dry for a few hours before sleeping on it.