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Old 07-02-2015, 02:29 PM   #21
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The Coot's rudder stays where it is set in normal conditions and adjusts with little effort.

Kar-KEEN-ez Koot
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Old 07-02-2015, 04:00 PM   #22
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Originally Posted by AusCan View Post
My rudder fails rule #3. I haven't measured it but from this old photo I have, but the rudder stock appears to be only about 10% back from the leading edge.

I'd assume this would require more force to turn the rudder, although my steering seems light, even though its cable driven and the rudder is quite large.
The force required to turn the rudder greatly increases with speed. At hull speed it would be much less of an issue. If you think about a rudder with no leading edge, only about half of the water coming off the propeller would hit the rudder. As you add more leading edge, a greater percentage of the water off the propeller hits the rudder. At slow speeds under power, the water from the prop hitting the rudder is what pushes the stern over. More leading edge equals more force on the rudder equals more steering force. Some boats such as sail boats use a much larger rudder to use the flow of the water over the hull as the force against the rudder. Your boat may fall into that category when moving at cruising speed. But when going slow or docking, it is the water coming off the prop hitting the rudder that gives you steerage.


I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
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Old 07-02-2015, 09:08 PM   #23
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Da rudder please

In the thread call a "rudder to be thankful for"around post 33 I posted a video and some spect on the schilling rudder I built. I could not be happier.

Here is a video on how well a fishtail rudder can work.[URL="
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Old 07-02-2015, 09:40 PM   #24
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Thanks for the rudder lesson guys. I'm happy with my system, but it's nice to know the how's & why's.

I've never had an issue with reversing, but it's something I always do at low speed. I do feel a bit of pressure on the rudder when surfing waves, but the hull shape generally handles the situation very well.
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Old 07-02-2015, 11:52 PM   #25
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Ditto what everyone has said about Mike Thompson. I never met the guy, but I think I would have really liked him. His generosity in sharing his experience was matched by his insightful write-ups.
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Old 07-03-2015, 05:01 AM   #26
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Found this about Great Harbors with testing to confirm results: Fishtail Rudders Great harbour - Great Harbour Trawlers
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Old 07-03-2015, 06:08 AM   #27
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Originally Posted by bglad View Post
Found this about Great Harbors with testing to confirm results: Fishtail Rudders Great harbour - Great Harbour Trawlers
Interesting. This is good information but at the same time it is confusing. They tested by doing circles and turns. My issue with the rudder is in docking a single engine boat. The Great Harbours are twin engine boats with bow thrusters and I would have thought docking would be a non issue compared to us single engine guys. The fish tail rudder does significantly improve low speed manueverability so I guess the operator can rely more on steering and less on his thruster and engines when docking but it does sound like they solved a problem that didn't exist with the Great Harbours.

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