Of my four boats I mostly paddle my Romany. At 16 feet and with a good deal of rocker, it is a highly responsive craft. At the end of the day, however, it is only 16 feet in length, and I paddle with folks who are in boats as long as 17.5-18 feet in length. It seems that when I am amongst them I have to work a wee bit harder to keep up. Therefore, I have reasoned, I "need" to add one more boat to my chaotic collection in the garage. I need just one more, a long and sleek cruiser so I can more easily keep up. Turns out that I may be only half right.
The hull speed, or top speed, of a displacement hull is determined by its length. The longer the kayak or sailboat the higher the speed at which it will top out (tow it faster and it will start to climb out of its hole...but that is a digression for another discussion). Now, with kayaks we talk not only about hull (top) speed but also cruising speed, the speed that can be efficiently maintained over the long haul by an "average" paddler. I have been thinking that my top speed is more around the cruising speed of the long guys and that I was working much harder to keep up. Then I read an interesting article about hull designs on Sea Kayaker e-articles.
The article discusses tests on hulls that reveal that, while length does determine ultimate top speed, the resistances of all these boats going through the water is about the same up to speeds around 4-4.5 knots. Ergo, it takes about the same effort to keep a boat of any length around the cruising speed mark. Above 4.5 knots, the friction of water against the skin of the boat becomes the major factor in resistance and, hence, effort to maintain speed. Consequently, it takes lots more effort to drive a boat from cruising speed up to maximum or hull speed...regardless of its length but about the same effort to keep all hulls around 4 knots.
As it turns out, the best way to reduce the effort needed is by reducing the wetted surface and making the boat narrower. This, of course, may result in a design with less initial stability and make some paddlers uncomfortable. I wonder if Impex's Force boats fit this description. In any event, it appears that the modifications I had planned for my Romany won't solve my problem. Back to the gym.
Paddle safe...
DS
11 comments:
I feel a very tangeble difference between my Romany HV, and the Nordkapp. The Romany is 16ft vrs the Nordkapp at 18ft. The Nordkapp is 1 inch narrower.
I presume it feels like the Nordkapp is faster. Is it really or do you feel less resistance at cruising speeds because it is narrower?
Are you trying to convince yourself that you don't need one more boat? (What has Lady Linda put in your coffee?) That you will just paddle with us slower guys?
Part of what slows you down is taking time to take in all the sights and sounds (and smells) of the experience, some of which you capture to share with others. A longer boat won't help you here, but understanding paddling partners will for they enjoy the same.
A longer boat of same or similar hull design will be, in my opinion, be a bit faster. More importantly, again IMHO, provide more cargo carrying ability for touring.
But, the same engine is still providing the power. When all is said and done, the difference may be similar to the arguement that many spout for using a feathered paddle (less wind resistance), and may make more difference/sense if you were going for a medal.
I still think you need one more kayak, because you WANT one!
Perhaps you also need a "taster" for what LL is slipping to you. Hmmm, maybe she is playing a recorded message while you sleep. . .
I always felt it was less resistance because it was longer with the different hull shape. I hadn't realized it may be because of the width, or maybe the combination with the different hull shape ... until this morning.
For the record, JB, LL has been away since Sunday. I am just evolving to a higher plane of consciousness and social responsibility and blather.
Guard your coffee from my potion then . . . something's gotta be done about this state of mind your in !!!
Silbs, the Nordkapp is a good fast boat. I really liked mine.
If you have the possibility try the Skim Distance, though it might be hard to find one in the US. I paddled one in Italy for a month and a half, and it is both a stable and a fast boat. I managed to sustain over 5.5 knots for a fair time, with a fully loaded boat, and I'm not really that fit.
Rene', you've re-wetted my desire to try the Nordkapp. The is, by the way, a skim in Milwaukee. Sweet Sue is proud that she owns the only one this side of the pond..
forget not about comfort... you can have the fastest yak in the world, but if comfort is compromised... the fun factor and speed deminish if you are sitting on the beach.
I usually try to shy away from hull speed arguments. Of course each person as an individual can notice differences from boat to boat, but how that may not matter much in a group since the variances are often pretty subtle. There easily comes a point where only a real athlete will tell the difference. Most of us just want to keep up with our non-athlete friends and not be worn out at the end of the day.
You know I have a Romany, Explorer, and the Alaw bach. I can tell the Romany is a tad slower than the longer boats, but to be honest, it's not much. The bigger difference to me is how a longer boat moves through waves. My experience is the longer boat will move more smoothly through our shorter sets in the great lakes & smaller bodies of water. Of course I do notice a big change in maneuverability between the Explorer and the Romany. Of course you don't necessarily have to sacrifice maneuverability either. Kayaks like the Nordkapp, Acuta, or the Alaw are all pretty nimble for long boats.
All good thoughts and advise. Thanks
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