Pool leak at tile grout around skimmer

I have an in-ground pool and have have a slow leak. I was able to track down where the leak was by just letting the water leak to its lowest point. The leak is at the input of the skimmer. Some of the tile grout that binds with the plastic skimmer has deteriorated away.

Curious, does the tile grout actually provide the water sealant or is it just built on top of something else that provides the water sealant?

Wondering if I have a leak under the tile grout or if I can I just replace the tile and grout that bonds with the plastic skimmer and be ok.

Thanks.

I hope someone responds to this. i have always wondered about the tile and grout in a pool as well. I don't believe grout can ever be a seal but how does one repair a leak that is located behind tile without having to remove the tile and likely replace all the tile since there is a good chance that the tile isnt made anymore.

The tile is not normally the primary water seal; the gunite is. And you're right -- you can't fix that without getting behind the tile. Of course, if you seal all the tile in that area, you'll probably slow the leak.