Washed out!

I have a 18x33 AG that was here when we bought the house. This is my first pool and I am learning a lot on this forum. My problem is the sand has been washed out from under the liner directly below the skimmer. It goes about 4 inches back and is about a foot long across. How do I go about fixing this? Do I need to drain some water so I can lift this area up and replace the sand or is there another method? Maybe pulling it back with a plunger or something?

Thanks in advance.

Does anyone know how I might go about fixing this problem????

This does not sound too serious, unless the reason it has washed out is a leak in the liner or something. Take some sand and pile it back in there, you can use a sledge hammer like a battering ram to pack it back in there, then pile dirt around the outer edge to seal it in and pack it down too.

Ultimately, I have to ask though, why do you suppose the sand washed out? What caused it?

The ground around the area is dry so I went into the pool and looked at the liner and there is a patch just above the cove. I am assuming this was the cause of the wash out.
If I understand you right, I can just take some sand, force this back under the liner, and pack it in tight? I don’t need to lift the liner up at all to replace the sand?
Thanks for your help

No, just get it back in there really good. Is the patch holding?

Yes, the patch seems to be holding fine. I don’t see any signs of wetness on the ground and I am not losing any water. I Did the bucket test to make sure.
I appreciate your help in this matter.
Thanks.