Thanks everyone for answering the Q about the CD Extreme.
It seems to me that the Extreme has a fair amount of rocker for a longer boat. I was wondering how the other longer boats discussed in this topic compare, especially ones that are faster. Secondly, how do they handle in nasty conditions compared to the Extreme, which I’ve heard does well. And I think the Extreme turns/responds very well when edged for it’s length, how about the others? How about stability?
Many of the responses used the water line length as the main component of speed, and width secondary. I can’t help but think (this is where I get into trouble) that the wetted surface’s length, width, shape/flair (swede, fish) total wetted area; the displacement depth; and the amount of rocker all play a part in 1. efficiency at a given speed and 2. the available top end speed. Especially rocker, i.e. a highly rockered boat may have significantly different performance characteristics than a non-rockered boat of equal length and/or even equal wetted surface at the water line. These performance characteristics also include sea-worthiness, tracking, and maneuverability.
And I would think trim can also play a part, albeit minor perhaps… Add a little weight in the bow or move the seat forward and you can often eke out a little more top end speed. With these longer boats, I would imagine with some weight forward, you could “pop” or plane the boat in shallow water. One of my boats is a NDK Poseidon, which has notoriously low top-end speed for a 16 foot boat. I find it interesting to play around with the trim in both shallow and deep water. It does seem to improve bow down. Mariner seats are adjustable I believe.
A lot of rambling on my part, but an interesting topic. Any thoughts?
Tom
Too subjective - Go test paddle!
Yes, all of that and more plays a role - but most is beyond discussion except in the most general sense. You can discuss the physics - but not the feel. One characteristic will be described differently by all depending in size, skill, where they paddle, and a big factor: what they’ve paddled before.
People who have paddled the faster boats in rougher stuff will likely tell you the one they paddled was fine, maybe even great. On the flip side, many will assume some boats to be bad - but haven’t paddled them in that. Bottom line, some will work better than others - for you!
If you are used to a shorter hull, there will be an adjustment going longer. Mostly in turning and handling conditions.
Rocker is a particularly hard element to discuss rationally. How much is right depends on who is paddling and where - and also depends on all the other design elements. No “right” answer. Which have more than others is also hard to say without a side by side on a flat floor. Pictures of my Q700 would lead you to believe it has next to no rocker - but I can assure you it does. Some Brit designs look to have lots and don’t - others do. An upswept bow does not guarantee more rocker, just less LWL. Rocker is not listed as a spec as it would be very misleading.
You have identified a great short list. Hard to go too wrong with any of those - but one will likely suit you better. On top of that, all can be outfitted more to your liking - and you adjust to them as well.
Go test paddle - or bite the bullet and get one if it’s hard to find test boats. Buy used and resell at no loss - or take QCC up on that 30 day test paddle - or buy one of the others new and take the depreciation hit if you sell.
It’s worth long drives if you can get good long test paddles.
I Agree With Greyak, And…
Greyak is right. You can only get so much from the general specs. You have to demo to really know how it feels…
And ask yourself this question: In kayaking, the different between a fast boat, and the fastest boats, is only a couple MPH. IF you are racing, you want every MPH you can get, but if not, you might want to give up an extra MPH for a boat that just feels good to you…
If you are frustrated about a buddy who is always ahead of you on trips, a new boat might not help. Tsunami Chuck is always going to be ahead on me on every trip, even if I am in my 18’ Shearwater and he takes Kathy’s Pungo!
I found this link interesting
http://www.seakayakermag.com/PDFs/Kayak_Reviews_Info.pdf
There are a couple hydrostatic measurements, prismatic coefficient and block coefficent, that, while not exactly the same as a rocker measurement, probably have some correlation. I believe the more refined drag prediction formulas take those into account.
I guess I don't need to repeat what I said in the other topic, just than to say unless you are at a pretty athletic level, you aren't going to be able to push any boat in what's generally considered to be fast single size (say greater than 14 ft waterline length long, less than 23 inches wide), faster than any other by more than a tenth of a mph or two for any significant distance. The drag curve begins climbing pretty steeply around 4.5 knots for most all of them.
So you think about other considerations, fit, storage, stability, handling, what's available locally, etc. And your intended use, sprinting or covering distance, etc. In my case I ruled out anything with a rudder, first. That eliminated many boats right away (including the Extreme). I went into the local store not even thinking Caribou, but there was one sitting on the floor, and it was the best-looking hardshell I'd ever seen. I couldn't resist it. The people in the store said it was one of their favorites, for what that was worth. It was the only boat I test paddled, and felt stable enough and comfortable enough, so it's mine now. May not be the last one I get, but it wasn't a bad first choice.
Mike
Engine not the boat
The strength of the paddler often counts for more than the hull speed of the kayak.
Find a kayak you feel good about paddling that is not a dog and unless you intend to race, you'll be fine.
(Last Saturday, I was finally able to easily keep pace with a friend who is a very strong paddler. I loaned her my Elaho and I was in my Aquanaut.)
Any of the boats mentioned are fast enough touring boats. Get the one that handles best the range of conditions you will be paddling
Pet peeves
Tom wrote:
A lot of rambling on my part, but an interesting topic. Any thoughts?
This topic often turns up on p.net(and rightful so - it’s darn interesting).
When comparing boats, please consider to which degree the boat allows the paddler to work efficiently.
Does the cockpit allow you to paddle with the legs together? (so you can pump the legs).
Does the boat have a proper footrest/rudder control? Preferable a T-bar though a well crafted butterfly control works too.
Is the boat narrow, so you can insert the blade close to the centerline? Is the seat properly raised?
Does the boat/seat have enough room for rotating the body? (don’t pad a seakayak like it was a WW boat).
/Peter
17 ft long! Some design & Sci LINKS
an lot more if upswept ends.
To an earlier comment - about beam being secondary - I’d say (waterline) beam can be more important for efficiency, as skinny works at all speeds and length only at higher speeds. Not that simple though as both are interdependent.
If you go narrower, but same length - boat will sink deeper. Partly why short boats are so fat. Skinner is better for speed - IF the hull is long enough to balance that. Longer is good for speed - IF the boat is narrow enough to allow you to push it to speeds where you can take advantage of the longer faster wave-making.
Narrower also tends to generate less wave energy - which allows kayaks and other skinny craft to pretty easily surpass “hull speed” under human power.
Some other design related links you may enjoy (and can explain some of teh science a lot better than I can):
http://www.qcckayaks.com/resources/speakboat1.asp
http://www.qcckayaks.com/resources/speakboat2.asp
http://www.greenval.com/shape_part1.html
http://www.greenval.com/shape_part2.html
http://www.greenval.com/shape_part3.html
http://www.nswseakayaker.asn.au/mag/33/design.html
http://www.ihpva.org/pipermail/hpv-boats/2001q1/000751.html
http://www.oneoceankayaks.com/smhydro/hydro.htm
trim thigh braces
I trimmed thigh braces on glider about 2 in so could pump knees. Paddling a boat is like pedaling a bike- it all starts with your legs. Extreme is heavy and high volume. I much prefer a wesr side eft. Very stable and much faster and lighter. Even a narrow boat like the bolt can be paddled well thru chop as you and boat and and 7 ft long paddle are one. Think and believe the boat is 7 ft wide because paddle is 7 ft long. Smile and relax and wiggle your hips. Do not buy a heavy boat. Think used kevlar
Other useful info
http://www.marinerkayaks.com/
Go to the downloads page and look over the drag prediction spreadsheets. A tremendous amount of info is there for the taking.
Thanks again
Wow, this is great. Lots of discussion and advice. Thanks everyone !
I live on Lake Michigan and paddle often. The Poseidon is great for surf and really rough stuff, but not for speed. Which is why my search is not only for a speedster, but also a seaworthy speedster that can handle Great Lakes’ nastiest.
I was a very competitive marathon canoe racer years back and now work out regularly, so my fitness and power are good and I am used to squirrelly boats. But regularly paddling in 30-45 degree, rough water, has led me away from the fringe designs such as the racing sit-on top surf-skis (talk about squirrelly).
Well, looks like I will need to search out a few boats and try them. I know where I can paddle a QCC 700, but the others may be more difficult. It’s tough because it can take month’s to learn what a boat can or cannot do, so I think the “buy, try, and sell if you don’t like it” will end up being the mission.
Happy paddling.
Tom
Easy solution - skip the others! L