Boat Building Forum

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Re: The Long Boat Myth
By:Nick Schade - Guillemot Kayaks
Date: 6/10/2009, 8:57 am
In Response To: Re: The Long Boat Myth (Kudzu)

: I am letting the software (FREE!Ship Plus) calculate it. I am assuming it is
: based on the wetted hull surface/area. Therefore waterline.

I believe Free!Ship uses John Winters' "Kaper" model for drag prediction. This model is based on empirical testing that Sea Kayaker Magazine did back in the '80s. It attempts to model wave drag due to waterline length as well as frictional drag due to wetted surface area.

: But you bring up a good point, when I said 15' boat that was referring to
: LOA. I need to edit this and at reference the water line length with the
: LOA.

You could create a simple design with plumb ends so that LOA equals LWL. This would provide better results with regards to my other comments.

BTW: Good work on this. I often get people talking about getting a faster boat, when what they really need is a faster motor. Some people can not paddle hard enough for a 15' boat to start getting slowed down by its "hull speed".

Messages In This Thread

Skin-on-Frame: Fast, Playful SOF *Pic*
Michael Collins -- 6/8/2009, 11:10 pm
Re: Skin-on-Frame: Fast, Playful SOF
Aaron H -- 6/9/2009, 3:36 pm
Re: Skin-on-Frame: Fast, Playful SOF
Michael Collins -- 6/9/2009, 10:39 pm
Re: Skin-on-Frame: Fast, Playful SOF
Aaron H -- 6/10/2009, 6:11 pm
Re: Skin-on-Frame: Fast, Playful SOF
Brian Scaborough -- 6/10/2009, 10:21 am
Re: Skin-on-Frame: Fast, Playful SOF
John D. -- 6/10/2009, 3:02 pm
The Long Boat Myth *LINK* *Pic*
Kudzu -- 6/9/2009, 7:43 pm
Re: The Long Boat Myth
Mike Savage -- 6/11/2009, 7:01 pm
Re: The Long Boat Myth
Johne -- 6/11/2009, 12:08 pm
Re: The Long Boat Myth
Michael -- 6/11/2009, 10:23 am
Re: The Long Boat Myth *Pic*
Allan -- 6/11/2009, 3:54 am
Re: The Long Boat Myth
Bill Hamm -- 6/11/2009, 9:50 am
Re: The Long Boat Myth
Kudzu -- 6/11/2009, 11:56 am
Re: The Long Boat Myth
Michael Collins -- 6/11/2009, 1:58 pm
Re: The Long Boat Myth
Kudzu -- 6/11/2009, 5:33 pm
Re: The Long Boat Myth
Bill Hamm -- 6/13/2009, 1:23 am
Re: The Long Boat Myth
Terry Haines -- 6/18/2009, 11:45 pm
Re: The Long Boat Myth
Bill Hamm -- 6/19/2009, 11:39 am
Re: The Long Boat Myth
John F Monroe -- 6/24/2009, 5:42 am
Re: The Long Boat Myth
Terry Haines -- 6/19/2009, 6:33 pm
Re: The Long Boat Myth
Bill Hamm -- 6/11/2009, 1:26 pm
Re: The Long Boat Myth
Kudzu -- 6/11/2009, 7:42 am
Re: The Long Boat Myth
Allan -- 6/11/2009, 8:02 am
Re: The Long Boat Myth
Kudzu -- 6/11/2009, 9:19 am
Re: The Long Boat Myth
West -- 6/11/2009, 4:23 am
Re: The Long Boat Myth
Allan -- 6/11/2009, 7:45 am
Re: The Long Boat Myth
Ken Brunton -- 6/10/2009, 11:13 am
Re: The Long Boat Myth
Kudzu -- 6/10/2009, 1:40 pm
Re: The Long Boat Myth
Michael Collins -- 6/10/2009, 2:16 pm
Re: The Long Boat Myth
Kudzu -- 6/10/2009, 7:52 pm
Re: The Long Boat Myth
Bill Hamm -- 6/10/2009, 3:44 pm
Re: The Long Boat Myth
Michael Collins -- 6/9/2009, 10:26 pm
Re: The Long Boat Myth
Kudzu -- 6/10/2009, 8:33 am
Re: The Long Boat Myth
Nick Schade - Guillemot Kayaks -- 6/10/2009, 8:49 am
Re: The Long Boat Myth
Kudzu -- 6/10/2009, 1:08 pm
Re: The Long Boat Myth
Nick Schade - Guillemot Kayaks -- 6/11/2009, 10:35 am
Hey Nick
Kudzu -- 6/12/2009, 10:18 am
Single change??
Allan -- 6/12/2009, 6:47 pm
Re: The Long Boat Myth
Kudzu -- 6/11/2009, 12:04 pm
Re: The Long Boat Myth
Glen Smith -- 6/9/2009, 8:16 pm
Re: The Long Boat Myth
Kudzu -- 6/10/2009, 8:17 am
Re: The Long Boat Myth
Nick Schade - Guillemot Kayaks -- 6/10/2009, 8:57 am
Re: Skin-on-Frame: Fast, Playful SOF
Bill Hamm -- 6/9/2009, 1:15 am
Re: Skin-on-Frame: Fast, Playful SOF
Brian Scaborough -- 6/9/2009, 8:32 am
Re: Skin-on-Frame: Fast, Playful SOF
wwfloyd -- 6/10/2009, 7:47 pm
Re: Skin-on-Frame: Fast, Playful SOF
Bill Hamm -- 6/11/2009, 1:00 am
Re: Skin-on-Frame: Fast, Playful SOF *LINK* *Pic*
Tom Yost -- 6/9/2009, 10:24 am
Re: Skin-on-Frame: Fast, Playful SOF
Bill Hamm -- 6/9/2009, 8:28 pm
Re: Skin-on-Frame: Fast, Playful SOF
Tom Yost -- 6/10/2009, 12:41 am
LMAO!
Robert N Pruden -- 6/9/2009, 2:43 pm
Re: LMAO! *Pic*
Tom Yost -- 6/9/2009, 6:13 pm
Re: LMAO!
Bill Hamm -- 6/9/2009, 8:30 pm
Re: Skin-on-Frame: Fast, Playful SOF
Brian Scaborough -- 6/9/2009, 10:40 am
Re: Skin-on-Frame: Fast, Playful SOF
Michael Collins -- 6/9/2009, 11:11 pm
Re: Skin-on-Frame: Fast, Playful SOF
Brian Scaborough -- 6/10/2009, 1:00 pm
Balancing Gear
Michael Collins -- 6/10/2009, 2:01 pm
Re: Balancing Gear
Bill Hamm -- 6/10/2009, 3:40 pm
Re: Balancing Gear *LINK*
Brian Scaborough -- 6/10/2009, 2:27 pm
Re: Skin-on-Frame: Fast, Playful SOF *Pic*
Tom Yost -- 6/9/2009, 11:01 am
I've done that, too, but only with the Guinness.
Robert N Pruden -- 6/9/2009, 2:46 pm
Re: Skin-on-Frame: Fast, Playful SOF
Brian Scarborough -- 6/9/2009, 12:00 am
Rider, Ranger?
Michael Collins -- 6/9/2009, 11:07 pm
Re: Rider, Ranger?
Bill Hamm -- 6/10/2009, 2:27 am