Since the hinge falls near the balance point of the boats, you can easily lift them, push the swivel to the center of the rack, and walk around to the back of the car setting the boats down on the back rack.Then there's plenty of room on the sides of the rack for masts, planks and boombags.
The design has evolved. The new model uses the same basic principle, but now it has feet which hit the ground and a support that folds down to keep the ends of the boats off the ground. The foam pad is no longer necessary and it's much easer to work.
You take everthing off the same way. Here's Cathy unloading the boats. The pictures are clickable.
First the masts and planks come off
By that time, the platform is unstrapped from the roofrack, and she can swivel the boats around, slide them to the edge of the roof, and let them hinge down.
The white thing on the ground is a piece of foam for a no-scuff landing. This is no longer necessary with the improved design.
Next you unstrap the boats and tilt them to the ground.
This thing works like a charm. Safe and solid on the car, easy on the back. This season I'm going to give it legs so it's more stable in the down position.