They cheated me out of seeing how the pitch controls worked.
Under water maneuverability works just like movement in the air. One or more props change speed slightly so the force exerted on the arm(s) increase/decrease and the whole unit rolls/pitches. The big difference it that underwater the blades are rotating much slower because of the density difference between water and sir.
Right at the very end of the vid there is a close-up of the pitch control in action, if that is what you are looking to see.