Last year we had a few hairline plaster cracks and we used putty to fill them ourselves without draining the pool. We don't know if any of the cracks in the deep areas of the pool were leaking pool water but we determined with dye one near the surface was leaking. After puttying the leak stopped. We don't know the cause of the cracks - they are all tiny in width but some are long. Through this winter the pool vacuum has chipped away at some of the putty work we did - probably because the putty was not flattened with a putty knife or similar - so the cracks are starting to show again, and there are new cracks showing also. The water is too cold for us to dive down and and patch ourselves now, and last year it was really hard to perform the patching, having to dive hundreds of times! We're wondering several things - Can a professional do a better patch job than we did, and if so can they dive down and do it, or does the pool have to be drained? Who would we call to perform the patches for us? Or is it best to just get the whole thing replastered? $$$$!