I have a 20X40 grecian vinyl pool. Shallow end is just above waist high. Maybe 3.5'. I'm not 100% sure. Deep end is 8.5' with a diving board. The shallow end takes up 45% of the pool, then slopes to the deep end. We moved into our house exactly two months ago. We have three kids, 7-1/2, 4-1/2, and 2-1/2. None of them were competent swimmers when we moved in. They had played in pools, but hadn't really learned to swim. It took three weeks for the oldest to come out of the life jacket. She started jumping off the side of the pool going a little closer to the deep end each time. She went from shallow end jumps to the diving board in about two hours. Little sister(middle child) wanted to be like big sister, so she worked her way around. Little brother was not going to be left out. He worked his way around too. Now, he is the only one required to wear a flotation device. They all swim all over the pool. There is no telling how many times they jump off the diving board every day. Definitely plan for the future because they will progress quickly.