Help, please

Can someone tell me more about this drive system? Picture is from '91:

 

Tractor

Hey Olli, those appear to be tractor or pod drives.

Which have been around a while for larger craft. there basicly stern drive lower ends mounted through the hull and turn like 90 degrees in both directions. they pull rather than push, and are said to be more efficent the inboards because they have clean water to draw from ( no running gear ). Also there's no shaft angle to try to push the hull up out of the water.

They also offer improved monuvering over an inboard. Both volvo-penta and mercruiser have just come out with there own version, with some big builders signing on.

I'm sure someone with more technical data will come along.

hope this helps

 

Those are fixed pods which incorporate rudders on the legs.