The Mercedes one works like an A/C compressor clutch if I remember correctly.

 

would'nt the clutch on the seadoo's supercharger be a safety feature because they come in and out of the water? i dont own one but i have ridden a few of the gxp's and those are supposed to be supercharged, they would rev out for that second or two when it was above the water.

just my .02

 

Safety how? Because the engine revs so much faster out of the water? That makes sense, I guess it would take too much programing to make the computer control the engine's acceleration.
As I am writing this, I realize more and more that it has to be why. An automobile would never see a situation similar to a boat coming out of the water. If you get the tires in the air over a bump, the engine still has significant resistance by turning the trans and drivetrain.
You would have to disconnect the torque converter or the flywheel from a car suddenly to replicate the loss in drag that a boat sees when it gets air, since a jet pump or propeller offer very little flywheel effect.
I vote for your answer, One Slow4.8.