There were some questions about the saddle configuration on the Apollo Scooter. I grabbed some images that show that aspect a bit further below:
Two of the AV-2 Evolution scooters at the end of the dock at DiveTech/Cobalt Coast Resort. The two plates comprising the saddle readily bolt on to the scooter assembly.
Another view of the saddle. The saddle uses a speed control rod assembly that connects with the power control button on the scooter. You can pull it out in segments allowing incremental speed control. This is also the thing that I thought adding a deadman leash/kill switch to would be a good idea for deeper scooter free diving.
Josh in the saddle
Rick ascending in the saddle. You don't have to have your arms up but it does provide a good signal to the safety diver that you haven't passed out, streamlines a bit and might even aid in the odd collision, ouch. You can imagine how minor displacements of your fins could easily turn things and even barrel rolls. After a while you don't even think about turning and simply do it. I only have video of two free dives shot by the safety divers hence the limited images, most of the images were shot by myself on board the scooter during the dives.