I'm sure you are right about prop inefficiency, Bob. My main can push the boat at about 7 knots on 70 horsepower while the wing barely gets over 5 knots with my 70 hp wing running flat out. Having the rudder over 8 to 10 degrees doesn't help. I have a three-blade Gori folding prop. We had expected that the lack of thrust across the rudder would be a big deal when we trolled with the wing engine, running 1.5 to 2 knots, but there is (barely) adequate rudder capacity to handle the boat at that low speed in the kind of seas that are calm enough for fishing. Rudder authority gets decent above 3 knots and is more than adequate at 5 knots, as long as you give the AP enough authority (20 to 22 degrees minimum). Of course, the boat will only back in circles no matter how fast you go. We played around with the wing once with the premise of getting some "twin engine" steerage effects out of it in case my thrusters died. It was awkward to use the two different control systems, one on each side of the instrument panel, but it kind of worked. Backing the main and revving the wing in forward turned the boat at lot faster than rudder alone, and also at zero speed. In a "thruster emergency", that's how I'd augment my rudder when coming into the dock. Clearly not nearly as good as twins from that regard, each of them off center, but better than nothing. The idea of an extra rudder and better prop would improve situation a great deal, I'm sure. But given how incredibly reliable well- maintained diesel engines are, I'm content with the compromises I've got. I personally view the wing as something to maintain control of the boat while I figure out how to fix the main. Regards John John On Sep 15, 2009, at 6:00 PM, bob Austin wrote: > John, > Have you ever considered a separate rudder for the wing engine? I > have a friend who had several refinements: 1 a rudder, 2 counter > rotating from the main, 3 controlable pitch rather than folding. He > was quite successful in using it for close quarters maneuvering. > > My observation is that most of the wings are so in-effecient because > they use less than maximum effeciency props. For example, using a > Martec, vs a Maxiprop, the latter being more effecient. > > Take care, > > Bob Austin

A single engine shaft / prop configuration is often cited as being good. except for entanglement of prop in fishing nets. Many fishing boats have cages around their single prop to eliminate this problem. However the cage itself introduces turbulence. How much this decreases eficiency is a question mark. Has anyone heard of a case wherea fishing trawler was converted to recreational use and the cage subsequently removed? Any data on changes in efficiency? Arild