You may have installed your vinyl liner swimming pool years ago when your children were smaller. At that time, they wanted a pool with a deep end for diving. Unless you had a very large swimming pool, this left you very little shallow end.
Now as time marches on, the children have moved out and started their own lives. Your swimming pool is still there with the deep end but you do not dive. You prefer a pool that does not have a deep end. You would like to be able to use your whole pool to stand or play.
When you are ready to install a new liner, that deep end can be filled in and your new deep end could have a depth of 5' or 6'. The deep end is normally filled in with gravel and that is covered with vermiculite. You now will have more of a usable swimming pool. Space will now allow you to play volleyball, basketball or any other type of game in your swimming pool.
You will find out that your kids now will enjoy your pool more when they visit with you. If you now have grandchildren, they will love being able to use the whole pool and play games.