I was doing maintenance on the pool yesterday and it must have been leaking for some time cuz the finish is bubbling on the outside pool wall. I almost didn't notice it but I ran my hand down the wall and could feel it and then I knew. It's on the bottom left of the skimmer box outside wall.
I searched and found this thread and I'm going to try what the OP ended up doing but with Epoxy Gator Aqua Stick, instead of the mighty puddy and see how that works. I do not have the energy to fight with a new seal and drain the water below the skimmer over and over if I can't fix the leak.
Hope it works.