Turtle position in Jiu-Jitsu and grappling is when you are belly down, using your knees and elbows as support.
Master Rickson Gracie teaches you to deal with a training partner on top, trying to submit you or take your back.
First, he addresses the awareness of keeping mobile and agile for protection. Then, he shows one option to grab a leg and use your body weight to turnover and land on top.
Rickson teases what comes next: "This is the first (technique) of many."