As someone who is extremely afraid of heights, it is highly unlikely that I will ever go skydiving. However, that doesn't mean I can't appreciate the physics of it. For instance, skydivers accelerate when they go down because the force of gravity is greater than the drag on their bodies. Also, the acceleration in question will always be 9.81 m/s^2 as that is the acceleration due to gravity. But when the parachute is opened, the increase in surface area creates an increase in drag, therefore making the skydiver slow down.