To do it, you need maximum speed.
The key point is to push on your heels when you enter in the second part of the move, fin first.
Doing that, you will be able to connect the section, what is many much better than a simple 360° on the white water.
SUPer : l’Ours (Patrice Guénolé) on GONGSUP.

Source : Team GONGSUP, Daviator behind the camera and the paddle 😉