Infinity Pool Shelf / Cupholder

This is probably too esoteric a need to be useful to most people, but if you spend a lot of time in an infinity pool then you'll know the frustration of wanting to stand near the edge of the pool since that's generally got the best view / vibe, only to realize that there's nowhere to put your drink/phone/speaker, because there's nothing to stop a mild splash or wave from sending them off the side of the building.
Having to hold your stuff above the water or walk to the other side of the pool every time you want to adjust the music or have a drink is a compromise that people who aren't willing to spend a couple dozen hours over-engineering a cupholder have to make.

If your infinity pool happens to have an edge that's