Whenever I mention "Inboard Propellers" to friends with catamarans, their eyes seem to glaze over and they start looking off toward the horizon!
Boats with inboard propellers - the stbd prop turns left and port turns right when going ahead - have some big advantages over the more common "outboard propeller" set-ups and I believe would provide a great advantage on catamarans
The last big boat
I drove (95 ft) was set-up this way. After the innitial learning
curve, I came to appreciate the superior handling characteristics the inboard configuration gave the vessel.
Essentially - I could "walk" the vessel sideways which enabled me to park the boat
in places I'd previously steer away from.
Tight quarters? No Problem.
beam on or off the dock
? No Problem.
? No Problem.
The trick was to lock the rudder(s) hard over to push the stern in the direction you wanted to go - and use the prop walk of the other (reversing) prop to control the angle of approach. Primary control was in the throttles with no need to turn the rudder(s) at all.
It provides a similar effect of a bow thruster and I could have driven the boat sideways all the way across the harbour, if need be.
supply & crew boats are commonly set-up this way because it affords far better control at slow speeds and more thrust at cruising speeds.
The only draw-back I found was that the vessel will no longer rotate on her axis, as expected, with one engine
in forward and the other in reverse... which, IMHO, is a small loss compaired to the major gain in safe docking
I'm just curious why catamaran
owners / builders never seem to set their propulsion
systems in this beneficial configuration.