The back roll entry is also easier on the body, especially because scuba divers are laden with a lot of extra weight, especially with the oxygen tank on their backs. By diving in back-first, you’re letting the tank lead the way and avoiding possible injury.

“The impact of a feet-first dive is hard on your joints and can cause an injury if you don’t hit the water accurately,” A-1 Scuba & Travel Aquatic Center of Littleton, Colo., explains in a blog post. “Similarly, a headfirst dive can cause an injury from the impact or from loose gear.”