Thanks for the ideas. I'm tired of fighting with the "ladder pad" that I bought with the ladder because it never stays under the ladder. It always ends up somewhere else in the pool and I was concerned about the liner near the steps.

Instead of a bath mat I was thinking of possibly using one of the outdoor brush mats as such


I think something like this would be heavy enough to stay in place.

Then again even a water noodle zip tied in place somehow would be perfect. They are cheap enough to experiment with