Besides tradition and arguable aesthetic merits, can someone point me to a factual discussion on why would one want or not want bow and stern overhangs? From a purely functional on the water prospective, please?
One "functional" argument that I can think of is that the waterline lenghtens as you go down the face of waves or as the waves come at you, effectively providing faster top speed when needed to surf or go thru surf, while keepint the overall length shorter for ease of paddling in flatter water... But that's a "gut feeling" thing so I may as well be wrong...
I would tend to dismiss an argument about balancing the boat in side winds, as that can be accomplished by other means.
Just look at the recent post of the "Vintage 20" greenlander that has probably 3 feet of bow nad stern not touching the water most of the time. How would this 20 foot boat with 17 feet waterline compare (paddling-wise) to a 17 foot QCC-ish type of hull (with similar rocker and hull profile otherwise)?
The other thing I have been visualizing is that if I am to remove the overhang, that has to change the hull profile near the bow and stern. How would this affect the handling of the boat, assuming we keep as much of the rest of the hull intact?
Thanks!
Overhang good for riding up on ice?
Would allow you to ride up on to ice, rather than slamming into it, if you didn’t tip over while the bow was up on the ice and the stern was still in the water.
they let me know my toggles are
still attached (klunk!)
A plumb bow is faster then the elfin
shape of those cute Brit boats.
Man am I ever going to catch hell from my friends across the pond who we paddle with each year in the keys.
Cheers,
JackL
But is it?
If they are the same waterline length and as similar shapes as possible otherwise (assuming the overhang weight and effect in the air is negilgible).
Why would one or the other offer a benefit while paddling, purely from a standpoint of interaction with the water?
To clarify my query: I suppose sliding over ice, catching weeds/leaves, wind effects, weight, overall length etc. are all factors to consider, but I am only asking about on-water/in-water effects. E.g. does the longer waterline length when the bow/stern are riding thru waves or in wind chop not be beneficial? Again, starting from a point where the waterline length in still water are the same for both kayaks, but the WLL for the upswept one will increas in some cases where the WLL for the other one will not.
Problems here:
1. There ARE no kayaks that are the same LWL and hullform otherwise (and it’s the “otherwise” that matters more*).
2. There are few who have paddle both types in different conditions enough to really compare, and who don’t have some bias/favoritism one way or another due to other factors that would taint their impressions. Paddle one a while and it’s likely the other will feel odd to you. Most here will just be defending whatever they paddle and justifying it based on things they’ve been told by people doing same before them…
3. Even among those who have used both in a range of conditions, and aren’t really in any camp on this, you have to refer back to #1.
Want science? Read Winters, etc. Not Pnet.
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- Things like the fullness or fineness of the ends, gunnels being “pinched” or not, resulting waterplane area and prismatic coefficient differences, cross section shapes, etc… Just looking at the pointiness of the ends is a lot like just looking at the chine edge sharpness. Not very predictive of anything on their own.
Except the ice thing! Long overhangs also create a less abrupt silhouette when viewed from low angle (more stealth on flat water hunting seals), and being a nice thing to grab to lift (onto the drying racks above reach of those seal hunters’ dogs).
Want use/conditions input and purpose built comparison? Look at Inuit Greenland qajaq vs. Aleut single hole Baidarka - being used as originally intended - not modern recreational uses.
Brit boats are Greenland influenced while QCC/EPIC and such have more Baidarka-like lines (maybe not influenced, but coming to same conclusions about fuller ends and such).
More generalization, but at least pointing (pun intended) to there being all sorts of good reasons for all sorts of shapes. Doesn’t mean the differences don’t matter, or that folks are in the optimal shape for their uses. Just that we do this for recreation and the functionally of what we choose isn’t usually as important as how we feel about it. We live in a culture that likes to “sell the sizzle, not the steak.”
- Things like the fullness or fineness of the ends, gunnels being “pinched” or not, resulting waterplane area and prismatic coefficient differences, cross section shapes, etc… Just looking at the pointiness of the ends is a lot like just looking at the chine edge sharpness. Not very predictive of anything on their own.
catching caribou?
I read someplace, maybe Derek Hutchinson, that the really pointy bows were for hunting caribou. The caribou would be driven into a river and the kayaker would entangle the bow in the antlers and hold the caribou for another person to kill.
I assume they had good bracing skills…
Actually, I’m asking for custom built
I’m seriously thinking of building my own kayak (skin on frame most likely) and thus have the freedom to pick/design the shape any way I please.
It eludes me as to why I would want any significant overhang (excet may be up to 1/2 foot to minimize seaweed/leaves catching).
But I would like to hear if there is actually any good reason from paddling dynamics point to consider having a longer overhang, aside from hunting/sliding over ice sheets as I am very unlikely to do either -
I realize it is not possible to just chop-off the overhang and keep the rest intact, but if I had to choose b/w overhang or not, why would I want one or the other in a boat that will have the main design criteria be: low above water volume, easy to roll, relatively fast/efficient to paddle at a brisk pace, and with a preference for maneuverability over tracking?
Derek should know …
After all, he invented pointy bows!
And probably caribou, too …
http://www.AquaDynology.com/
Delphinus
First SOF? Just split the difference.
Do what looks right to you. The rest of the things you need to figure out (for a more non-traditional/keelson up custom) are a lot more important.
One more thing to consider here though, pointer ends are easier to stretch and sew skin over (and not have any other than the one deck seam, nothing on along stem or stern that messes up the cutwater/extends below waterline).
darn it all
You mean to say my kayak is not well-suited for hunting caribou? Now you tell me.
Flare
If you want flare in the sides an overhang seems to be a natural consequence on a skin on frame kayak. The bifid bow on a baidarka may be a way to achieve flare without an overhang.
Thank you both! (n/m)
no message
faster till that plumb bow hangs up with
near anything floating on the surface! Nothing P.O.'s me more than having to stop and back up to rid debris (leaves, seaweed, etc) after failing at ‘bouncing’ the bow of my Wenonah ‘Javelin’ outrigger to rid the hitchhikers! Doesn’t take much debris to noticeably slow my forward motion, or make a racket! Doesn’t really happen all that often, but it is a pisser when it does happen. Have a bud who paddles marathon/sprint boats who has the same complaint about his plumb bows. They are fast though!
Not only rides up on ice…
… but also on those pesky mangrove roots and most don’t have rudders to tangle. However those high pointy bows do catch the low branches.
Blame flat debris filled water…
…not the bow rake. With even very small waves, wakes and chop it becomes a non issue. More plumb can actually clear easier then.
Leaves on flat water seem to be the things that cling, and more raked bow kayaks I’ve owned (SOF, Sparrow Hawk, Pintail, Shearwater…) have picked up leaves just as much or more than my QCC (I suspect due to sharper leading edges and flatter surfaces) and had to bounce them once in a while too.
Does it matter?
I have no background to get into this kind of discussion, probably would need some boat design experience, but am curious as to why you are asking. The bow and stern overhang, or lack thereof, are usually attached to a hull that could have a variety of other characteristics inbetween. So for a given boat and its overhang, functionality would be be about a lot more like rocker, hull stability profile, fit, speed, features etc. The overhang would probably end up being something that was subservient to the rest of it in choosing a kayak.
So I am curious as to why this part of the boat is the focus.
Better response on another BBS?
The blue herons KayakFoundry forum might be a better source:
http://www.blueheronkayaks.com/phpBB2/index.php
That or the Kayak Building Bulletin Board:
http://www.kayakforum.com/
Simply because those sites are geared more towards self-built boats.
Just curious …
Probably not the most important part of the boat, you are right.
Winters
Greyak said "Want science? Read Winters, etc. Not Pnet."
Best advice I have ever read on Pnet. Maybe the only good advice? :-)