First, let me say that there are simply no cementatious interior finishes out there that are perfectly smooth. If you spend enough time in the water particularly if you are playing games or rough housing, you will get little "raspberries" or sore spots on your feet and toes.
We use a product called pebbletec. It is classified as an exposed aggregate finish. Even though the stone aggregate is exposed, the stones themselves are rounded and not abrasive. The beauty of pebbletec finish is it's greatest feature along with it's 15 yr. warranty. Pebbletec comes in a variety of colors. Another product we are using is an exposed aggregate which is buffed with a buffing tool after it is applied to give the smoothest interior finish available in a concrete pool! I will tell you more about this via the blog or by appointment, as we are the only pool company currently offering this product. I want to keep this exclusive as long as possible.
Finally a traditional or basic plaster finish that can be done in color or white. It has a smooth surface but no exposed aggregate in it. It looks clean and is the least expensive of all interior finishes.