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Re: Catmaran kayak? I have one --- almost
By:Bill Hamm
Date: 5/27/2008, 5:27 pm

: Hi Bill - I just stumbled across your thread - I had the same idea about a
: year ago. I've been mulling it since, and over the Christmas break I built
: a 1/4 scale model of a preliminary design for a catamaran kayak. The hulls
: are long and narrow, 16'4" by 6", max draft will be about
: 8-9", overall beam I'm trying to keep to 24". It's basically a
: skinny hull cut in half down the middle. Seating will be from a hung seat
: above the waterline, so I guess it will technically be a SOT.

: The boat is designed as a swimmer escort and rescue kayak - the major design
: goal is to be able to transport a patient on a hammock behind the paddler
: above the waterline to reduce hypothermia. The extra load will require a
: sliding seat for the paddler to trim the boat. It is also meant to act as
: a platform for long distance swimmers to eat, drink, rest, whatever.
: Ideally, it will be stable enough that the paddler can turn around and
: move around to aid the patient/swimmer. I think it will work well as a
: chase boat at paddle events as well. I'd also like it to be fast, able to
: function on the open ocean, etc. etc.

: A plastic wrap test on the model went pretty well (it appeared to have very
: low drag), and I am currently gearing up to make a prototype starting in
: the next week or two. It will be a big experiment, as the model didn't
: give a lot of info about paddling dynamics, and there's a lot to figure
: out. I've thought about doing some software modeling, but that won't help
: with the dynamics either, so I am going to just forge ahead and make a
: boat. I plan to do the first prototype as a Yost-style SOF. The hulls will
: be nearly flat on the inside as suggested by you and Mike - they're so
: narrow they actually look more like airplane wings on edge. But hey, my
: Dad was a wind-tunnel model-maker at Boeing and my brothers and I grew up
: making balsa airplanes, not boats, so I guess that has something to do
: with it. The biggest challenges I see at this point is hull torsional
: stiffness and weight.

: I have a detailed photo sequence of the model construction. I've been meaning
: to put it all together to share on this site - I'm glad you asked your
: question as it gave me the impetus to start. The link below has just a few
: so far.

: I wanted to call the boat the "Sea Sled" but the name was taken by
: a fast speedboat catamaran from the early 20th century (now defunct,
: though). I'm toying with the name "Cutter", which has a nice
: double meaning - USCG Cutters are used for rescue, of course, but
: "cutter" is also a term for a light, fast sleigh pulled by a
: single horse, which I think is appropriate.

: Well, I guess this is maybe more info than necessary, but I've been thinking
: about this for a long time. Let me know what you think - better photos
: later, Carl

Hi Carl,

Very interesting, you're further along than I am. The one I'm thinking of is quite a bit narrower though, around 21" beam. Basically a surfski split in half, though the hulls do have to be much deeper to compensate for the reduction in displacement. Definately will need a rudder, will look silly but with the hulls so close together there's only a need for one rudder from the bottom (or stern) of one hull.

I would though suggest that making the individual hulls more full at the bows should help them not bury as much in waves. Very narrow hulls tend to do that. There's a term for the relative fullness of the hulls that right now escapes me (senior moment ).

Will be looking forward to seeing your progress. Hey I can wait and learn from someone else mistakes (for once ).

Bill H.

Messages In This Thread

Seeking: catmaran kayak?
Bill Hamm -- 5/18/2008, 1:26 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/21/2008, 1:43 am
Re: Seeking: catmaran kayak?
Mike Savage -- 5/21/2008, 6:35 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/22/2008, 1:25 am
Catmaran kayak? I have one --- almost *LINK*
Carl Delo -- 5/27/2008, 1:30 am
Re: Catmaran kayak? I have one --- almost
Chris Ostlind -- 5/29/2008, 9:11 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/30/2008, 1:18 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/30/2008, 10:23 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/1/2008, 2:54 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 6/1/2008, 11:41 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 1:53 am
Re: Catmaran kayak? I have one --- almost *LINK*
Carl Delo -- 6/2/2008, 9:36 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 3:26 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 6/2/2008, 5:43 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 5:54 pm
Re: Catmaran kayak? I have one --- almost
Mike Savage -- 6/3/2008, 3:26 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/3/2008, 5:55 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/3/2008, 3:51 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 6/2/2008, 6:43 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/3/2008, 1:58 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 1:45 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/30/2008, 11:08 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/30/2008, 11:23 am
Re: Catmaran kayak? I have one --- almost------Web
Dan Caouette (CSFW)------WebKitFormBoundaryqtsCtZA -- 5/30/2008, 11:57 am
Re: Catmaran kayak? Floatation
Carl Delo -- 5/30/2008, 10:28 pm
Re: Catmaran kayak? I have one --- almost------Web
Bill Hamm -- 5/30/2008, 1:21 pm
Re: Catmaran kayak? I have one --- almost *LINK*
Dan Caouette (CSFW) -- 5/29/2008, 1:55 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/30/2008, 12:02 am
Just Curious.
John Monroe -- 5/29/2008, 4:38 am
Re: Just Curious.
Bill Hamm -- 5/30/2008, 10:46 am
Re: Just Curious.
Carl Delo -- 5/30/2008, 11:32 am
Re: Just Curious.
Bill Hamm -- 5/30/2008, 1:24 pm
Re: Just Curious.
Bill Hamm -- 5/30/2008, 1:08 pm
Re: Just Curious.
Carl Delo -- 5/30/2008, 10:48 pm
Re: Just Curious.
Bill Hamm -- 5/30/2008, 11:06 pm
Re: Just Curious.
Carl Delo -- 5/30/2008, 11:45 pm
Re: Just Curious.
Bill Hamm -- 5/31/2008, 9:24 am
Re: Just Curious.
Mike Savage -- 5/29/2008, 7:09 am
Re: Just Curious.
Bill Hamm -- 5/30/2008, 10:37 am
Re: Just Curious.
Mike Savage -- 5/30/2008, 2:53 pm
Re: Just Curious.
John Monroe -- 5/30/2008, 5:26 am
Re: Just Curious.
Mike Savage -- 5/30/2008, 6:37 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:43 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/27/2008, 5:37 pm
Re: Catmaran kayak? I have one --- almost *Pic*
Carl Delo -- 5/27/2008, 11:55 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:43 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/29/2008, 12:28 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:51 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/27/2008, 5:27 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/27/2008, 6:15 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:47 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/27/2008, 6:32 pm
Re: Catmaran kayak? I have one --- almost
Mike Savage -- 5/27/2008, 7:04 am
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/27/2008, 12:03 pm
Re: Seeking: catmaran kayak?
Scott Shurlow -- 5/20/2008, 6:36 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/21/2008, 1:22 am
Re: Seeking: catmaran kayak? *Pic*
Tom Yost -- 5/18/2008, 8:05 pm
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/19/2008, 1:28 am
Re: Seeking: catmaran kayak? *Pic*
Tom Yost -- 5/19/2008, 2:02 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/20/2008, 1:21 am
Re: Seeking: catmaran kayak? *Pic*
Tom Yost -- 5/20/2008, 2:35 pm
Re: Seeking: catmaran kayak?
Randy Ricchi -- 5/19/2008, 9:34 pm
Re: Seeking: catmaran kayak?
Tom Yost -- 5/20/2008, 2:26 pm
Re: Seeking: catmaran kayak? *Pic*
John Monroe -- 5/18/2008, 4:46 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/19/2008, 1:26 am