Speed and efficiency

[charlieboy]

Hi

I think I am edging closer to splashing some cash for a better boat..

I did the Oban Sea Kayak race yesterday, found the trip around Kerrera very hard going and coming from a background of reasonable success in distance running and cycling events, now know how it feels to cross a finish line with 'looser' written all over you. I have not seen the official results but think I there maybe only ten boats behind me in a field of fifty, 55 minutes behind the first-in.

In partial mitigation (I hope) I did have what a suspect was the slowest and shittiest boat in the event, a plastic capella. I am tall and thin so furthermore I am not well conected to the inside of what is already a whale of a boat.

What I would like to know is- all other variables being equal roughly by what percentage would performance in such an event be determined by the boat one was paddling? Or put another way, if we had all been forced to paddle plastic Capellas, where would I have finished? I had planned to try out both Knordkapp LV and Etain LV which were lined up con the beach at the finish courtesy of the Oban Sea Kayak Centre for demo purposes but was too knackered and depressed so just went home.

I don't think I'm ever going to be into kayak racing but speed and efficiency are important to my paddling and I am curious to know how much of a difference the boat itself makes in reality.

Cheers.

[johnb]

I think this article may help answer that question....
http://www.seakayakermag.com/2007/07e-n ... tkayak.htm
So long as you can actually handle the kayak, the effect of waterline length starts kicking in when you paddle over about 4.5 knots. Below that speed wetted surface is important and the longer kayaks don't have such an advantage. So if the whole field were in plastic Capellas it would mean the faster paddlers hitting the max speed of the boat and encountering high resistance as they try to drive it faster.

[Chris Bolton]

At race speeds, boat design and weight make a big difference. From your cycle racing, consider how much difference it would make to ride a mountain bike in a road race - but because of the way drag on a boat builds up as you go nearer to its theoretical maximum, kayaks will show more difference.

Chris

[TechnoEngineer]

There was an article I came across a few years ago which demonstrated that, not only is the length important, but the length to width ratio - of the waterline. Note that boats with a lot of rocker have a shorter waterline. Hence for racing you don't want a manoeuvrable boat with lots of rocker - such as the Capella. You would have been a lot faster in the Nordkapp.

[scotty]

I have a plastic capella and an epic 18,the speed difference at cruising speed(4.5mph) is negligable but the faster you go the larger the advantage of the long boat is. I had not seen the link Johnb posted before but from personal experience it would seem accurate. So if you can paddle race distance at near 6mph you will cover noticably more ground in a longer boat.

[Aled]

More on the LWL/BWL here: http://soundrowers.org/DeterminingKayakClassifications.aspx