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Re: Wish I knew....
By:Craig
Date: 10/23/2001, 11:31 pm
In Response To: Wish I knew.... (Craig Bumgarner)

As a newbie, I've been trying valiantly to educate myself on this, as demoing wood boats isn't especially feasible for me (but I'm not about to go fiberglass!). I found the Pygmy site perhaps the most helpful, in combination with back issues of Sea Kayaker and the tests they've done. The most interesting is the comparison of turning times on one of their pages, and the comparison of side views, between the Arctic Tern 17 and the Queen Charlotte. The key variable seems to be the dihedral near the ends and the "skeg" effect generated by the shape; the AT17 is fairly typical for hard-chine boats, while the QC17 chine stays very low and produces ends with unusually shallow V shapes--ergo, less skeg effect and resistance to turning. Their own data show the QC17 as unusually fast turning, both flat and when leaned--and test language suggests it may benefit from a skeg or rudder for tracking, not so much for weathercocking as simply to settle down a willingness to yaw. One would suspect that the opposite effect might be seen in the Squeedunk Cormorant, in which a point is made of carrying the chine more upward than usual as it reaches the ends, to settle the boat a bit deeper in the water and enhance tracking (at least when level).

Having said all that, I'm leaning toward a Spring Run--which I may need to shorten to 16-2 or so for storage reasons; hopefully should still float this 200-pounder fine for daytripping on Lake Michigan. I'm open to any educated comments!

: I too am intrigued with this question. I built a CLC 17LT and it tracks dead
: straight but takes 6-8 sweeps to turn it around. I then designed my own
: S&G at 16' x 20" and put in 3" of rocker (about 1" over the
: 17LT), hoping among other things, to make the boat more manuverable. Alas,
: though I am very happy with the boat in other ways, it is no more
: maneuverable than the 17LT. SOF Greenland boats seem similar to most S&G
: single chine designs.

: My guess is that in a chine boat like a SOF Greenland Kayak and a S&G single
: chine boat, the hull bottom forms a skeg forward and aft at the ends,
: making it harder to spin. I don't know what the answer is, but I suspect
: the center of the boat has to, in some way, provide enough floatation to
: get the ends more out of the water. Increased rocker is only one element
: of this. In the case of my new 16 footer, I think I defeated the increase
: in rocker by going to less length and beam so that the entire boat sets
: deeper in the water, thus the ends set deeper as well, resisting turning.

: It is worth noting that a recent post to this board stated that the S&G
: version of the Guillemot is more of a tracker than the more maneuverable
: strip version.

: The other thing I think I notice is that boats that maneuver well have more
: of their displacement propotioned towards the ends. That is, from
: underneath, they look more like cigars than elongated diamonds with
: long-drawn out, skinny ends. The Pintail, the Guillemot and the Wilderness
: Sealution, all manuverable boats have bottom profiles like this. I haven't
: figured out how to translate this into the hard chine model however.

: I hope someone can post an example of a kayak of the SOF Greenland type or a
: S&G single chine that the afore mentioned boats known for their
: maneuverability.

: Craig

Messages In This Thread

How much rocker?
Linda -- 10/21/2001, 6:15 pm
comparing apples to oranges
Paul G. Jacobson -- 10/22/2001, 11:39 pm
Re: comparing apples to oranges
Linda -- 10/23/2001, 11:15 pm
Re: How much rocker?
Brian Nystrom -- 10/22/2001, 2:18 pm
Re: How much rocker?
Linda -- 10/22/2001, 9:24 pm
Re: How much rocker?
Brian Nystrom -- 10/23/2001, 1:02 pm
the perfect recipe for tippyness?
risto -- 10/23/2001, 1:32 pm
How much is 1/2 of nothing? ;) *NM*
Brian Nystrom -- 10/23/2001, 1:47 pm
1/2 of nothing? - SPLASH, Gurgle,... ;) *NM*
risto -- 10/23/2001, 1:51 pm
Wish I knew picture... *Pic*
Craig Bumgarner -- 10/22/2001, 12:14 pm
Wish I knew....
Craig Bumgarner -- 10/22/2001, 11:43 am
Re: Wish I knew....
Craig -- 10/23/2001, 11:31 pm
Re: Wish I knew....
Greg Stamer -- 10/22/2001, 12:11 pm
Re: Wish I knew....
Craig Bumgarner -- 10/22/2001, 12:26 pm
Drawing of Anas Acuta *Pic*
Craig Bumgarner -- 10/22/2001, 12:38 pm
Re: Drawing of Anas Acuta
Greg Stamer -- 10/22/2001, 5:10 pm
Re: Drawing of Anas Acuta
Linda -- 10/22/2001, 9:11 pm
Storm Roll. Congrats!
Greg Stamer -- 10/23/2001, 6:18 pm
Re: Drawing of Anas Acuta
Mike Hanks -- 10/22/2001, 9:53 pm
Derivations
Mike Scarborough -- 10/22/2001, 4:54 pm
Re: Derivations
Linda -- 10/22/2001, 9:04 pm
Re: Derivations
Brian Nystrom -- 10/23/2001, 1:20 pm
Not Much Help
Mike Scarborough -- 10/21/2001, 7:52 pm