Been searching around with little success on why the offshore racers with surface drives use rudders instead of vectored drives. What is their thinking?
I have my own ideas why it is, but would like to get some input to confirm my thinking on the matter. I get that they sacrifice maneuverability around the docks, but what is the perceived benefit when running at speed?

Hmmm, no takers yet? Ok, I'll start and if I'm way off someone call me on it.

I'm thinking the removal of the skeg provides cleaner undisturbed water to the props so they work more efficiently. More efficient prop equals more speed. Another benefit is the size and depth of the rudder can be optimized for the anticipated speeds to minimize water drag. At lower speeds the boat might be a little loose from not enough rudder in the water and docking will be a pain in the rear, but likely they don't care.

Another possible benefit, although probably less important, is when an engine lets go while running at high speed. In a case like this it might be possible to quickly trim the drive all the way up and maintain better control of the boat because the rudder remains in the water.

So, what am I missing?