Re: [Paddlewise] efficiency of multi-chines (was: perfect..... kit boat)

Read below for a few specific comments on the efficiency of multi-hull
chines and eskimo kayaks. Also a few comments on the benifits of chines
and on the Osprey HP.

 I've been reading paddlewise only very infrequently lately, since most of
my time has been taken working on a website that I am starting up. If
anyone wants a preview of it, go to http://www.yourplanetearth.com
Cheers,
Kevin
                         -------------------------------
                         |        Kevin Whilden         |
                         |     kwhilden_at_seanet.com      |
                         |   Kayak Academy Instructor   |
                         | http://www.halcyon.com/kayak |
                         -------------------------------

On Tue, 7 Dec 1999, Dave Kruger wrote:

> William J. Oetjen wrote:
> 
> > At the risk of making an already convoluted thread even more so,
> > I noticed that lots of people stated opinions about Tupperware,
> > shatterglass, and  kevlar, but no one specifically commented on any of
> > those glass/plywood/glass kit boats out there.  Since I am anxiously in
> > the market for one of them (most likely a Pygmy Osprey HP) I'd appreciate
> > hearing more about that.
> 
> I made one (Pygmy Osprey Std) and love it for day trips.  (It is a little small
> for multi-day trips for me -- but would be OK for somebody 50 lbs lighter.) 
> Definitely lighter and maybe stiffer (I think) than trad. FG layup.  Way cheaper
> than FG or plastic, IF you do not consider your labor an "expense."   But, you
> gotta love the assembly process.
> 
> Drawbacks:  the hydrodynamics can not quite approach those of hulls popped out
> of molds, even though mine is a "multi-chine" design.  Winters and Broze (among
> others) might be able to quantitate the difference, if enticed.
> 

If this is true, then why did the Aleut Eskimos build boats with
multi-chine hulls? I would suggest they may have thought multi-chine hulls
were better than rounded hulls, and I don't believe for a second that they
didn't have the technology to build a smoothly rounded hull. I am of the
opinion that they arrived on their classic baidairka design after
centuries of rigorous testing that would rival anything that we do today.
Note that I am not saying necessarily that multi-chine hulls are more
efficient than rounded hulls, but I am saying that they might  be better
in an overall sense.


> Strip-built boats avoid the chine problem, but at the addition of considerably
> more work than stitch-and-glue plywood kits.  Guillemot Kayaks
> (http://www.guillemot-kayaks.com/) has a great Web site, complete with a
> builder's Web board for trading hints and insults <g>.
> 
> Others will chime in on chines and their value as a turning edge -- Whilden,
> where are you?
> 

I am not convinced that the presence of chines is all that important for
turning. Rather it is the hull shape that matters (although I have few
ideas as to how it matters). I have paddled plenty of rounded hull boats
that carve turns admirably, and several hard chines boats that turn
listlessly. I do believe that all else being equal, chines may enhance
turning in a secondary way. 

However, I am quite convinced that hard chines have tremendous value when
surfing wind waves, ocean surf, or tidal rapids. They are also quite
valuable when paddling in quartering seas.

> BTW, the Osprey HP is pretty much a straight-ahead hull.  Have you considered
> the Arctic Tern or the Coho (both Pygmy Designs, if that is your preference)?
> 

Dave is right on here. Unless you are planning to compete or paddle really
fast, then you shouldn't buy the HP. At normal cruising speeds, the
efficiency advantage of the HP is practically nonexistant, and turning
disadvantage is quite significant.


> -- 
> Dave Kruger
> Astoria, OR
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