Hi, Bruce, I have a friend from Vancouver Island who had a very nicely-appointed Cape George 44 (ketch) built in Port Townsend. Someone talked him into a Hundested rig and he has had nothing but headaches with it. It is well-known that voyaging sailboats can benefit from having a "sailing" prop for long distances and a "cruising" prop for tidal waters, and, obviously, the Hundested makes it easier than changing props. It's my understanding that this system was designed for use in fishing boats, where the benefit is greater due to the varying load/speed requirements. Personally, I believe in simple machinery and systems, although I'll confess to having feathering wheel on my sailboat for obvious reasons. Your design concept sounds simple and interesting. I have some experience with a 12V71 driving a jackshaft, gear-belted to air clutches on opposing shafts. I guess the same thing could be done reasonably well the other way 'round. Is that how you'll do it? John "Seahorse" Reply to: John@Camm.us L. Bruce Jones writes, Does anyone out there have any experience with controllable pitch propellers? I believe that Hundsted is the leading brand with Sabb a close second. Can anyone comment on real world efficiency differences between CPPs and fixed pitch propellers? Also, what about reliability, resistance to damage, maintenance and repair-ability? I have some experience with variable pitch aircraft propellers but have never operated a powerboat equipped with CPP. On the passagemaker we're designing now we are considering a coaxial arrangement with two engines driving a single shaft. This is not so much for the sake of mechanical redundancy as it is for engine output efficiency. I would like to have 240 plus HP for when conditions are bad but normally we'll require less than 50 HP to run at a V/L of 1.0 at 9 knots and 3 nmpg. Running a 240 HP engine at 20% of output is not a good thing and its better to switch between the two 120 HP engines and put both on-line when needed. With this range of operating speed/output difference a CPP would seem to make sense. On our current boat we always carry a spare shaft and prop. Carrting a spare CPP is likely to be a major expense. Thoughts? Bruce --