Re: [Paddlewise] Rudders

Actually, the best part about the Sealine Rudder is how very effective the 
blade is.  I guess you just have to see it and use it to believe it.  I know 
that only Kiwis can make proper rudder systems :^), but this is actually a 
great improvement over US systems and I'll bet the blade is as good as 
anything else out there, world-wide. 

I too fear that the vertical blade is an accident waiting to happen.  It 
sticks up too far to not take abuse.  Even worse, I worry about the damage it 
could do to a paddler's body.  Fall on it, or meet it in a surf tumble, and 
you could get sliced, diced and impaled.  But then, real kayakers live for 
danger, or we wouldn't call them rudder "blades," right?

One other thing after a bit of experience with these systems -- blast the 
nifty foot pegs systems out after use.  They get to be a real challenge to 
adjust with a little sand and salt and normal fleet use.

Harold


In a message dated 10/4/01 6:25:37 PM Pacific Daylight Time, 
a.ferguson_at_chem.canterbury.ac.nz writes:

> >[Mary]
>  >I am not sure if you have looked at this system, but the blade is very
>  >different from usual rudder systems because it is much smaller.
>  
>  That means that is too short. The blade I have on a rudder with the same 
>  approach (vertical stowed blade) stood miles up in the air. The pivot 
could 
>  not have been any lower or it would have been under water, the support 
>  block usually touched the water, and the blade could not be any shorter to 
>  be effective. If the pivot is any lower there won't be enough mechanical 
>  strength/support for the blade which will bend or split the mounting block.
>  
>  >  The pivot
>  >point for the rudder is lower than a conventional system so consequently 
it
>  >does not have to drop down as far.
>  
>  If you put one of those on a Sea Yak the blade wouldn't even get wet - too 
>  short to reach the water.
>  
>  >   When the blade is retracted it comes up
>  >from the lower pivot point and it is shorter so it doesn't stick up very 
> far
>  >at all.  I didn't measure it but it didn't extend much farther from the 
> deck
>  >than a conventional rudder.
>  
>  That means it would only be long enough on a high decked kayak if the 
whole 
>  unit was mounted at water level otherwise the blade is too short for 
>  anything other than flat water paddling.
>  
>  >   It has less surface area so there is less wind
>  >drag when it is up.
>  
>  Even less efficient no matter how good the foil shape is.
>  
>  >The other thing I liked about the system was that the blade has a spring
>  >that causes the blade to retract if you forget to take up your rudder when
>  >you get into shallow water or get into heavy bull kelp,
>  
>  You mean drops the blade into the water, a string pulls it up(?). We do 
>  mean retract when we pull it out of the water? A properly designed system 
>  allows "kickup" at some predetermined load. The spring is a high-tech 
>  equivalent of a bit of bungy.
>  
>  Alex
***************************************************************************
PaddleWise Paddling Mailing List - Any opinions or suggestions expressed
here are solely those of the writer(s). You must assume the entire
responsibility for reliance upon them. All postings copyright the author.
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************