Conference unifix::sailing

    See note 558.
    
    The Scheel has been around for a number of years and works quite
    well (compared to a deep fin).

    
    Walt

    A friend of mine is awaiting delivery of a Catalina 34 with a winged
    keel.  He spoke to an engineer at Catalina who indicated that the
    winged boat will point 2 degrees higher than the finned keel.
    

    If you are interested in a winged keel for its shallow draft, then
    sailing around sandbars is the best idea (after deep water), as they 
    are certainly more fragile than other configurations.  As .1 mentioned,
    Henry Scheel's patented design is quite effective, relatively shallow
    for its performance, and _far_ more damage resistant.  Many Scheel
    keels are external cast lead or iron, so grounding results in a ding 
    as with any traditional external ballast, not a broken wing. 
    
    As to the relative performance of winged vs. non-winged keels of
    the same draft, it seems equally common sense to assume that one
    benefits from lower CG, end-plate effect, and perhaps some negative
    lift if there's enough dihedral (i.e., the wings each angle down from
    horizontal.)
    
    John.                                          

>>>  the winged boat will point 2 degrees higher than the finned keel
    
An interesting comment made by one of the Stars and Stripes design team
at the America's Cup seminar in the Mill a while back may be relevant
here. The effect on performance of many design changes is small, so 
small that verifying the increase (or decrease) in performance requires 
extensive, and careful, testing. In many cases the Stars and Stripes 
designers simply told Conner and crew that the new rudder or whatever 
was better. And the crew always came back and said 'right, it is better'. 

In this particular case, I am a little skeptical about the validity of
claim that the winged keel points two degrees higher. How was the
testing done? Under what conditions (calm, chop, light wind, heavy wind,
etc)? Is the winged keel less good under other conditions (eg,
downwind)? And, cynically, do you really expect Catalina to say that the 
winged keel is less good?

    I am designing a winged keel for the 36' boat I'm building. But
    in my case, I'm not looking for either reduced draft or better
    pointing, etc. I simply need to get as much ballast weight as far
    aft in the ballast as possible (to get the damn boat to trim level
    on its lines), and wings at the aft end of the keel offer a significant
    moment aft of the center of gravity. I've retained the original
    draft (of 6" 9") and keel configuration in order to retain the
    designer's lateral plane - I don't feel like mucking around with
    the boat's balance as designed (or with the structural arrangements).
    
    Ross Faneuf
    

    
    
    
    	I own an O'Day 272 with a winged keel. I can't say enough
    	on how well the boat handles in all weather conditions.
    	The draft is only 2'11" which takes time to get use to
    	after sailing boats with 6' drafts. We ran a ground trying
    	to get into the canal at cape ann and had no problems 
    	rocking her off.

RE:.5 by OCCAM::FANEUF 

>  I've retained the original draft (of 6" 9") and keel configuration 
> in order to retain the designer's lateral plane - I don't feel like 
> mucking around with the boat's balance as designed (or with the 
> structural arrangements).

As I understand it, a wing will affect the balance of the boat.  There
is a center of lateral pressure which is in front of the center of
lateral area due to the vortex that the flow under the keel is creating.
The wing will reduce the vortex, and will shift the center of lateral
pressure closer to the center of lateral area.  This will cause lee
helm.


Phil

    I HAVE A HUNTER 23 WITH WINGED KEEL I HAVE SAILED IT FOR THE LAST 2
    SEASONS AND VERY HAPPY WITH THE BOATS PERFORMANCE. IT GOES
    EXCEPTIONALLY WELL TO WINDWARD AND WITH A 2'3" DRAFT ALLOWS ME TO
    EXPLORE VERY THIN WATER.  I HAVE GROUNDED ON MUD AND HAVE HAD NO
    BAD EFFECTS OTHER THAN A LITTLE EMBARRASSMENT.