I’ve been doing research about skin on frame kayaks and it appears most designs are greenland style. I’m not interested in a sock for a kayak. There is a few designs of touring skin on fames and I can always modify the design as I will be building it. I am aware of Yost and will be getting Morris’s and Cunningham’s books. I have options… So my question is, what is the difference in shape between the two? Is the bottom half the same and the top half (deck) different? OR is there more to it. I’m looking for an efficient kayak with enough room to be comfortable. I currently have a Carolina 14.5 and will be building a 16-17 ft SOF. I’m not looking for suggestions on kits, just the technical differences in shape between touring and greenland kayaks.
Thanks,
scott
“Touring…”
includes a broad range of hull designs, including Greenland kayaks. The overriding similarity is enough length, generally around 16' and up, that makes for longer waterline to have enough speed potential to cover longer distance paddling.
What is distinctive about Greenland style touring boats go back to the construction method that is focused on 4 panel shape of the hull and a fairly flat deck over that. The hull shape is derived from the use of a keel stringer, two side stringers and the gunwales that create the sharp chines on the side. The keel and side stringers encapsulate and are reinforced by ribs underneath.
SOF also includes the Baidarka which is more round hulled. This is achieve by using 3 or 4 stringers on each side of the keel stringer.
Modern touring boats can have sharp chines and four panel (Greenland) design but it can also have multichined or rounded chines due to variety that can be achieved with modern composite and plastic contructions methods.
These are some of the elements of touring boat designs. Other elements include rocker, volume (length x depth x width), the distribution of volume (i.e. symetrical, fishform, swedeform), the shearline of the ends (upswept or plumb, or in between), etc.
If you're planning to build an sof, you should check out the Qajaq/USA as well as the building forum in kayakforums.com. Lots of builders who can comment on the elements of design to achieve the performance you looking for, e.g. tracking vs maneuverability, expedition vs day touring volume, etc.
Morris' book is very good and provides coverage of more than just Greenland style kayaks. Cunningham and Starr provide alternative mehtods to various steps of building the Greenland kayak, as well some advice on making assessories and basic skills.
If you want more an expedition SOF, get Wolfgang Brinks' book on Baidarka building. If you want see pics of the northern Pacific skinboats, including the baidarka, google David Zimmerly who has a website with pics and descriptions on the various PNW SOFs he has surveyed.
sing
vs?
Greenland boats cover a range of uses.
The fact that many US builder build super low volume rolling machines only reflects their interest in mastering the huge range of possible rolling techniques. Certainly not the only option.
Hunting boats tended to have more volume and freeboard (though still low compared to US commercial kayak designs) to carry equipment, deal with rough water, etc. The Baidarka’s are typically a bit more volume and can handle gear inside - but can also be very narrow and rounded hull more challenging. Designed for covering distance on big waters of PNW.
SOF is just a range of ways to build. What you build is up to you. I’m working on my first now - and I don’t want a sock either. More of a running shoe! Sounds like you want a loafer or amybe a shoebox? L
Seriously though, get and read Morris, Cunningham, and Starr (and Petersen’s Skin boats of Greenland if you can get a copy)- and understand you are free to pick and choose methods and improvise and adapt all of it. Take Sing’s advice and go to:
http://www.qajaqusa.org
and
http://www.kayakforum.com
Many on these sites have built SOF (and S&G, and strippers, and…). Many did fairly roomy variations on basic designs - and many later wished they’d gone a little narrower and lower volume. Most end up building more than one.
You can easily buy good used commercial touring boats at reasonable prices - why take the time and effort to build something like that? Take advantage of the ability to create something unique and better performing that really fits you well.
Greenland kayaks are touring
kayaks but more of “day touring”. If you want a roomy Greenland boat you can do that too. Greenland hull shape is an inefficient hard-chined (squared) shape that works very well very narrow. But if you’re going to go SOF I’d have to say you’ll have more resources to build a Greenland style but making them wide isn’t very desirable.
Greenland AND touring
While most Greenland style boats are quite narrow and low volume to facilitate rolling, reduce windage and increase their visual appeal, there’s no reason why you couldn’t design something with more room and even more chines.
Biadarka often had enough chines so make the hull appear rounded (I think I saw Brink’s book use 7 or 9 per side?). There’s nothing keeping you from building a multichined SOF with 3 or more chines per side to fill-out the hull.
One of the beautiful things about SOF construction is that it’s so affordable and fast that you can afford to expiroment with prototypes until you find the design that really inspires you. Throw out the rules, build what you want and then paddle it like you stole it.
Cheers,
Jed
inefficient?
I know that hard chines SLIGHTLY increase wetted surface - and so frictional drag - but what little I’ve seen with actual numbers shows it to be quite small.
Might matter in a race kayak with a top paddler - where 15 seconds over 10 miles matters - but by itself is not significant touring (and I think I’m pretty picky about efficiency issues).
Water flows and just doesn’t see “square” the same way the human eye does.
I think your point about the hard chines being more suited to narrow beam is dead on though. With narrow enough beam - it acts “round” enough. Go wide - and it will get pitched and pushed and the drag penalty will start to be felt.
I think the differences in efficiency attributed to hard chined designs has more to do with the short waterlines, excessive rocker, pinched ends, fat waists, and fishform shape of many hard chined hulls. These features impart other qualities that may be useful - but come at the expense of efficiency.
Consider the potential of a narrow beam hard chine design with long LWL, moderate rocker, fuller ends, and swedeform. This is my current experiment - I’ll report at some point.
It’s all balance
Take anyone that has made a wide Greenland kayak and you'll find they don't like it. Now look at other Arctic kayaks and you'll see the wider they get the rounder they are. But certainly a log is the most efficient shape, deviate from that and you lose. I'm not saying inefficient is always bad, You have to design the hull to act like you want it too and give and take, it just sounded like he was thinking of making a wide Greenland kayak and I'd encourage him to look at other designs. Wide and big is fine ya just have to keep things in balance.
Miss understanding
I think many of you missunderstood my need for space and width of the boat. After comparing the Perception and Wilderness systems catalogs, I noticed the lenth and width were very similar (traditional tour vs greenland). I have no issues with a narrow kayak. I’m more concerned about height issues. It seems most of the “true” greenland designs are worn like a sock. I asked about the need for thigh pads on one of the SOF sites and got the responce of its not neccesary, as they fit tight enough already. Although the coaming is smaller, that is a non issue as I’m making the coaming what ever size I choose. My concen is is upward knee height, which I realize is very changeable as well. Can anybody comment on the feel of sitting in a greeland yak? This more of an issue of me never sitting in a touring or greeland yak and not knowing how they feel.
Thanks,
scott
You’ve Answered Your Own Question…
which is that, as the builder, you have tremendous leeway in designing and building to the specs you want. One of the reasons that you can have a lower height on a Greenland SOF is that you’ll be sitting on a relatively thin pad, with your legs straight out in front. This is different from manufactured boats where you sit on a higher seat and your legs splayed and knees bent to maintain contact with the thigh braces. More deck height is needed for this sitting configuration. Greenland paddling technique is slightly different because of the use of the GP and the sitting position than that of the modern touring boats and modern (Euro) paddles. But, I leave it to others who want to get into describing paddling techniques.
As pointed out above though, if you looking for a replica of a Perception boat or Wilderness Systems boat, you may be better off just buying that boat. What extra you spent is save in time (time = $$ too). Some folks building SOF generally looking for a custom fit that is not readily available from a manufacturerer. For example my SOF is 17’x18"x5.5" deep (aft deck). This is not some specialty rolling boat but the boat I use for day touring. It’s snug but not at all like wearing a sock. The lower volume and windage makes in an easier boat for me to paddle in higher wind situations without weatherhelming issues. I like and paddle this boat not because I don’t have choices since I have three other long boats, 2 of which are production touring boats (higher volume).
sing
Thanks
"which is that, as the builder, you have tremendous leeway in designing and building to the specs you want."
I agree completely… However, if I’m using patterns then I need to know what the patterns feel like.
“One of the reasons that you can have a lower height on a Greenland SOF is that you’ll be sitting on a relatively thin pad, with your legs straight out in front. This is different from manufactured boats where you sit on a higher seat and your legs splayed and knees bent to maintain contact with the thigh braces.”
I was unaware of this and this is what I was looking for. Thanks
“What extra you spent is save in time (time = $$ too).”
I dissagree completely. Time is only money when you don’t enjoy what you are doing. If you enjoy it, then you can assume its cheaper as you will be improving your mental status and lessening your chances of seeing a counseler.
Thanks a bunch,
scott
Not A “Pattern…”
it is more a "recipe" that you can alter to suit your taste.
For example, if you wanted a high volume boat that is similar to a production boat, you certainly can build deeper (perhaps wider as well), and use thicker minicell foam to build up the higher seat. You can also have a larger cockpit, and tie in slabs of wood (padded later) to bridge the sides of the gunwales to the masik (front support beam for the cockpit) to effect thigh/knee braces. Voila! You have a Greenland shaped/looking boat that has an interior dimension similar to production boats and will require you to sit in a similar fashion.
sing
Zactly NM
Skin on frame kayaks
can be designed with the masik or knee beam to fit snug against your thigh or knee with your legs laying flat. This works fine for people who can hyperextend their knees and have flexable hamstrings. I prefer my kayaks to have padding under the deck were my knees will need bracing and have more room for an easier entry and exit. Some people find that paddling with their legs laying flat is not comfortable if their hamstring muscles aren’t loose. I feel most comfortable with my legs slightly bent. Commercial kayak cockpits will fit a wide variety of people and give you good knee bracing by bending your knees and adjusting the footpegs. You need to find out what feels best for you.
Does it have to be a homemade SOF?
If you want a SOF that does not “fit like a sock”, take a look at the Feathercraft Wisper.
If you are making your own to minimize cost, don’t bother. But if you are thinking of making your own SOF because you think a comfortable one is not available commercially, think again.