Is the skimmer plastic? Does it have a black bottom? If so, there is a kit for this. Check out black bottom skimmer repair - search.
Generally, the skimmer area of the pool can be sleeved with PVC if there is a leak
NO the leak is in the entrance to the skimmer, a grout line was broken when I had the pool replastered and the vibrations from the jackhammers did it. The plaster co. will not take responsibility for this. You have to actually determine that the skimmer is in fact leaking. Repair kits are available on the market just for this situation. However, the leak has to be at the very bottom or near bottom of the skimmer. Have you had a pressure test on the system?
turn the pool pump off,take off the cover of the pool skimmer box, The pool water level must be above the area where the skimmer box meets the pool wall. If it is not, add water to the pool until it is at least 1 inch above this seam.
Skimmer pool is a pool with side skimmers around
It would be easier to replace with a floating skimmer Check poolrite dragonfly
There is a special puddy you can buy from your local pool place to fix a cracked skimmer. It dries quickly & its easy to use. You may have to do this yearly. We have had to twice now.
diagram for skimmer for above ground pool
If this is an above ground pool you could just pull the old skimmer out cut the rusted section of metal out hit it with some rust converter, replace the section where there is no metal with a new metal forget about the old skimmer setup and replace it with a "floating pool skimmer" they do a better job any way.
Add thru the skimmer box
1. determine where your pool is leaking (liner or plumbing) and repair.