Corner-Boost.

Corner Boosts can be performed on almost all ledges by moving back and forth while prone. Once in the falling animation, press forward and unprone at the exact same time. Furthermore, if you prone the side of a hatch and move side to side and enter the falling animation, you can move forward and crouch late to get into certain positions, the only currently known one is Chalet Kitchen hatch. Make sure to crouch late and not hit the side of the hatch and prevent yourself to get onto the object