Subject: Re: [baidarka] Back to skegs for a minute
From: JRMcNeil@StateStreet.com
Date: Mon Oct 22 2001 - 09:58:31 EDT
James McNeil, a Skin-on-Frame-With-Skeg Owner:
I built a kayak with a great deal of rocker which caused it to lose it's
keel definition and to track very poorly, especially at planing speeds.
Another fellow from this list (Vernon Doucette) took a look at my boat and
suggested that I try a skeg. I built three or four plexiglass t-bars with
different heights and lengths and duct-taped them to my boat to test. I
found that a very small skeg had a big impact. Using this knowledge, I
crafted a wooden skeg with a two inch profile that's about eighteen inches
long. I affixed this by doweling into the keel and then applying generous
coats of gacoflex to the joint it makes with the skin. I attached it so
that it ends at the waterline when my boat is loaded.
The skeg causes several different behaviors in my boat. When under way it
resists wind-cocking in either direction. When at rest in a wind, it
leecocks to a greater degree if the wind is strong, but is about balanced
otherwise. It isn't large enough to cause problems turning, but it's like
backing a trailer up when you try to do anything in reverse. The most
noticeable problem it creates is in a following sea. It can be awkward
when a large wave accelerates the boat or hits it at a quartering angle.
I've never been broached, but I'm pretty sure the skeg isn't an asset when
trying to avoid it.
Brian Nystrom
<brian.nystrom@att. To: baidarka@paddlewise.net
net> cc:
Sent by: Subject: Re: [baidarka] Back to skegs for a minute
owner-baidarka@padd
lewise.net
10/20/01 11:17 AM
Please respond to
baidarka
Phil Ellis wrote:
> Brian,
>
> On the skeg thing, your point is well taken on the leecocking effect a
skeg
> would have if the boat was ballanced in the first place, but wouldn't it
> also improve directional stability under way?
Yes, but the boat will still turn downwind.
> And wouldn't it tend to
> prevent broaching on a following wave?
I don't believe so based on my experience with the YouKnowWhatKapp. I have
a
plastic boat with a retractable skeg and I found that under certain
following
sea conditions, I'm better off with the skeg up.
> Isn't that what the skegs are for on surfboards?
Possibly, but it's really an apples to oranges comparison. Surfers can move
around on the board to change their c/g, etc. at will, thus altering the
handling of the board. Kayakers can't. Consider also that a surfboard
without
skegs has no keel; a kayak does. There is also nothing to anchor the bow of
a
surfboard to the water. The narrow bow of a kayak serves as somewhat of a
forward skeg. Last, but not least, a surfboard is a planing hull. Except
when
surfing, a kayak isn't.
> H.C. Petersen notes (Skinboats of Greenland, pp.68-69) that experiments
with
> skegs (aka, steering fins) began in 1867 and that after the idea was
> described in an 1884 magazine article by Lars Moller, their use became
> widespread. Petersen says that the skegs were used to prevent the boat
from
> suddenly veering as the hunter was about to throw his harpoon, but
doesn't
> specify what the cause would be. It might be significant that this would
> also have been around the time that rifle hunting from kayaks became
> popular, and the magazine article mentioned above also described the
rifle
> holster and shooting screen.
I believe this is referring to them traveling forward in a straight line.
The
need for a skeg would obviously vary with the boat and the wind/water
conditions. If you're traveling upwind in a boat that weathercocks, no skeg
would be necessary.
Without reading the book, I really can't comment further. I have a copy on
the
way from Greenland. When it gets here, I'll check it out.
> Anyway, I'm curious about how they work and how much drag the lines
produce,
> and so on, and I can probably build one in less than an hour, so why not?
It certainly can't hurt to try it. If nothing else, it would be an
interesting
experiment. I'm not trying to discourage you; I'm just offering some
impirical
data.
> Somebody at the Delmarva had a strap-on rubber skeg (not sure I'd even
tell
> people I had something like that), but I didn't get a chance to try it
out.
Sounds kinky.
> Don't know where they got it.
Kayak_kinks.com perhaps? ;-)
> I also have part of an old photo from
> Skinboats in Greenland that shows a whole rack of West Greenland kayaks
and
> they all have skegs. I'll post it for the curious.
I think I've seen the same photo.
> On the other hand, Harvey Golden and John Brand have both built boats
> similar to mine, and neither one of them mentions the wind and wave
problem,
> so maybe it's just me.
Well, every skin boat is unique. No matter how carefully you follow a
design,
there will always be some variation. I've also found that the weight of the
paddler makes a HUGE difference in many boats, SOF or otherwise.
-- RegardsBrian
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