How do you fix a leak in a pool without draining it?

EpoxyBond pool putty cures completely underwater and offers an economical solution for filling small cracks and stopping leaks in concrete and gunite pools. It can also be used to repair chipped tiles. The product comes in black and white and, once cured, does not discolor, shrink or bend. To apply the putty for swimming pools, simply open the cartridge, mix the two putty products (the single-bar formula dispenses the products in 1 tablespoon) and then apply the mixed putty to the crack on the surface of the pool or spa.