The URL is:
http://www.youtube.com/watch?v=U60rx06Dmtk
Not sure how this particular drive works, but "surface piercing" drives are on the way. This setup has half the prop only in the water at speed.
The problem with them (for cruisers, not muscle boats) has always been this: The prop that will plane the boat over speeds the heck out of the engine on plane. Prop it for cruising, and the boat won't get on plane (unless it's grossly overpowered). The solution is in the form of a new system from Germany (where else!) that uses a variable pitch prop. In THIS case the prop location is fixed, not on a swivel. The prop has movable blades (like a turboprop airplane). For planing off a shallow pitch is used. When on plane, however, the ECU dials in more pitch until the desired rpm is obtained.
Advantages are a maximum fuel economy, since nothing is dragging in the water (no other system can equal it) and minimal engine wear since the motor run at the peak rpm for longevity--perfect for diesels. Draft is minimizes since only half of the prop extends below the hull, and individual blades can be replaced if you hit something. Finally, use of the rudder is minimized (with twin engines) since the ECU can "steer" the boat by altering the pitch of the prop(s) on each side, and without touching the throttles! Slick.
Here's what an Arenson race setup looks like. It THIS case the prop moves up and down, and also swivels (a bit) side to side. The system coming from Germany is attached right at the transom and is fixed.
Jeff
PS to Dog: Got any other info on the Carolina drive? Love to see it.
fastjeff attached the following image(s):
"...reality is not nearly as lovely as the world of Liberal Land. No wonder so many people want to go there." - Tom Sowell