Raise pool floor temporarily

OK, I might get a lot of laughs for this question, but... :o

My IG gunite pool goes from 3.5' to 6' deep. Is there any product out there that would allow me to temporarily "raise" the deep end to about 3.5'? I was thinking of something like a "platform" with legs that would sit on the bottom of the pool.

I was just trying to figure out a way to allow for my friends and I to play water volleyball without one team treading the 6' water while the other team is standing in 3.5' of water. I don't want to permanently raise the deep end because I have a slide and the kids like to jump/dive in sometimes.

Well, whatever you come up with, let us know! That sounds like a cool invention, however, i can see numerous issues right away that will likely make it unfeasile to build.

Most things would need to be weighed down otherwise they float, depending on the displacement of the product, it may need a lot of weight to keep it down, unless it's steel, in which case you probably won't get it out again due to weight.
Your "feet" under the platform would have to disperse the weight of the platform, the weights and people on the platform evenly and without damaging your liner.
The platform should not move for aforesaid reasons as well as chaffing the sides of the liner too.
Floor would likely need to be perforated otherwise you'll have a hard time getting it into and out of the pool.

Maybe you should just get taller friends

I noticed at a pool that was giving lessons to young kids that they tied milk crates together and weighted them down. This made the pool shallow enough for the young kids to stand with out being underwater. Do not know if this is a solution for you but it might be a start.

Hope this helps