Showing posts with label bow rudder. Show all posts
Showing posts with label bow rudder. Show all posts

Thursday, September 1, 2011

Kevlar Valley Avocet Review


What an absolutely fabulous play-boat for day paddles! Not too shabby on a multi-day trip either--both in terms of load carrying capacity and cruising speed.  I am 6', about 180lbs, 32" waist, 33" inseam and have gone on a 4-night camping trip in this boat comfortably.  For longer trips, a Nordkapp HS and the Avocet complements Nordy extremely well.

When I first paddled the Avocet I was surprised at the small speed difference between it and Nordkap HS. There is a distinct difference though and I could feel how effortless the glide in the Nordkapp was at a pace where Avocet hit the wall.  It's just not as noticeable as I expected it to be given the 2' difference in boat length.

I was very pleased with the stability profile of the Avocet which I found to be more similar to my Nordkapp than to a boat in Avocet's class--NDK Romany.  The Romany has a distinctly stronger primary which beginners would relish. I found that Romany fought my attempts to put the boat on edge. When it comes to secondary, the Avocet is way more stable on the edge than the Nordkapp HS but comparable to Nordkapp H2O. However amply rockered the Nordkapp may be, 2' difference in boat length makes a huge impact in maneuverability and in tracking as well.  The Avocet quite literally turns on a dime!  Bow rudder turns with the blade at your knees is a thing of magic.  Neither of these two boats can be paddled comfortably without a skeg in wind and waves--not unless you desire an extreme practice in edging and sweeping on one side, that is.

I absolutely loved the boat in surf! In the Nordkapp, I slide off the face of the wave broach and the straight part of the ride is over. In the Avocet I can steer and keep the boat going straight! Makes for much longer and controlled rides. At 16' it's not a surfing boat by any stretch of imagination but at least I have a shot at some control in it.  And did I say it is much more fun in the surf? :)  I had a chance to paddle the Avocet next to Romany in 10' breaking surf.  This is not a conclusive evaluation but Romany felt even easier to maneuver and spin on the wave crest.  It may have been that the conditions were somewhat different.  On the other hand, Romany does have a flatter and more square hull under the cockpit so it may be that it planes noticeably better than the Avocet and rises higher out of the water during runs enabling the skipper to do more.

The cockpit of the Avocet fits me very well. I miss the tight fit of the ocean cockpit of the Nordkapp but not the getting in and out of it part :) Thigh braces are not as fool-proof method for being one with your boat but I have not gotten to installing any extra padding--have not found the need for it really.  In the Nordkapp I did that promptly after a 4-5' breaking wave sucked me right out of the OCEAN cockpit! I added about an inch on the sides in the upper thigh area for better contact with the boat. In the case of the Avocet, I am at the very top of the fit bell curve and the fit is tight enough (surprisingly, adding some 70lbs of load on top of my own weight, did not seem to overwhelm the boat's carrying capacity).  Can't complain about the back band--it's small and could be much improved but for my paddling style it more than meets the need.  I have a fancy white-water Immersion Research back-band sitting in my garage but have not felt the need to replace the simple back support of the Avocet yet.  My back feels quite happy.

The boat is extremely easy to roll compared to Nordkapp HS.  Given that the Nordy is quite easy to roll in it's own right, this is quite a compliment.  The boat is light, lifts itself out of the water due to the upswept bow and stern, the cockpit is low in the back and wide on the sides so that it does not interfere with the hip snap.

The boat is Pro Kevlar but weighs about as much as my light layup fiberglass Nordkapp. I don't quite understand how this is possible given that it is smaller boat.  A clue may be in the 1/2-inch thick layer of gel coat on the foredecks. I can see the thickness where the foot pump outlet exits on the top deck. It's thick! Could probably take a full tsunami!  It's also cracked because the front deck oil-cans under my weight.  The foot pump adds a couple pounds to the total weight of the boat too.

In summary, a perfect day boat and play boat sea kayak. Distinctly slower but much more maneuverable than Nordkapp HS. Fast enough for casual paddling. Big enough for a week of camping out of the boat.  No shortcomings that I can find.  I give it a 9/10 because no kayak should get a 10. They are all compromises of one kind or another.

Let me know if you have specific questions.

Monday, April 19, 2010

Empirical Feel for the Paddle Length


My first paddle was made by Canon. It had a fiberglass shaft and nylon blades. It's 230cm long. I got it to propel myself in a barge of a kayak: the folding Folbot Greenland II double. That's a beast with 34" of beam and 17" cockpit height. Folbot recommended 260cm for that boat but 230cm worked for me as long as I but a few inches of padding on my seat and was able to clear the coaming.

Since then I slimmed down. First came a single Folbot Cooper with a 24" beam. After that an old Valley Nordkapp HS—my slimmest boat at 20.5". With slimming boats and increasing appetite and skills, my paddles shrunk too. First I got an all-fiberglass 215cm Lendal, then another Lendal shaft to go with the fiberglass blades—a carbon bent-shaft 210cm. For the past 6 months I've been paddling a loaner 210cm all-carbon Werner Ikelos.

All along the way, "shorter is better and more efficient" has been the word.

This past weekend, I went for a paddle on a shallow rocky West Branch of the DuPage river. For the first time in years I've brought out my 230cm fiberglass-plastic Canon weapon. Just wanted to see how it feels and what difference 20cm in length really makes. Did not really want to bang up the primary guns against the bottom either.

First impression—the paddle felt very comfortable and efficient for casual stroking. The weight was not noticeably different from my fiberglass Lendal and the paddling was not any harder due to extra length. Very quickly I noted that the shaft was not as stiff as Lendal or Werner. It felt more like a Greenland stick as it obviously flexed with every stroke. I kinda liked that… I also liked the longer reach at the beginning of the stroke. It seemed like I could put more into each stroke and apply more power if I wanted to. So I decided to want to…

That's where things started to break apart. First, it was hard to maintain a high angle stroke as the blade went too deep under water and was harder to take out of the water. There was also no way I could generate high-frequency cadence with the longer shaft. Even though the blades on this Canon Heritage paddle had much lower surface area than my Lendal Kinetic or Werner Ikelos, the longer shaft increased the arm of the lever to the point where even these smaller blades quickly exceeded my available power. So while a fresh 4.5-knot touring pace with a stroke somewhere between a high and a low-angle felt very relaxed comfortable and efficient, sprinting with this paddle was awkward. Shorter paddle definitely has an advantage here regardless of the blade size.

Then I tried maneuvering strokes. I loved the extra extension on the stern ruddering strokes. Put the paddle parallel to the boat and work the throttle to see-saw from a pry to a draw. The boat responded wonderfully. Longer blade gives greater leverage and since the loads during ruddering are relatively low on intensity, extra length is an advantage. Something makes me think that the speed and power involved in surfing would most likely overwhelm the hands wielding a longer weapon.

Extra length does not work so well on bow rudders either. I immediately got lost with upper hand somewhere in the sky, lower blade deep under water and the amount of strain on the body noticeably greater than with a shorter paddle. Positioning the blade was also more lethargic, fine control more elusive. This could be, in part, due to the fact that I have not used this paddle for a long time but the difference was so stark that I tend to dismiss this argument of disuse.

Sweep strokes with a longer paddle—you guessed it—are more efficient. Here the more power and leverage you have the better. Since the blade is farther away from the boat, both the turning and the supporting momentums benefit.

In summary, longer paddles have come in disrepute lately. After a few hours of paddling a low-tech cheap long paddle, I could see no prohibitive disadvantages to using it for casual paddling. Some maneuvering strokes and bracing may be a bit slower with the longer paddle; however, this lag is more than compensated by the additional leverage that a blade gains when it is used farther away from the hull. As long as the blade is not too big, a longer paddle seems perfectly appropriate for a non-technical paddler. Lower paddling angle is also known as less demanding on the upper body strength and seems more appropriate for people who are less physically fit.

Except for the stern rudder and sweep strokes, a longer paddle will most likely interfere with technical paddling strokes and intermediate-to-advanced maneuvers. Acceleration is sluggish, bow rudder is awkward, braces are slower, draw strokes seemed less efficient due to sinking blade. It also seems like a longer paddle would be more of a hindrance than help when rolling in rough water. Extra leverage will be nullified by the difficultly of maneuvering the blades into proper position.

At the end of the day, I expect that longer paddles will be back in vogue in the next decade or so.

Tuesday, January 26, 2010

THE TALE OF TWO BOW RUDDERS?


I am in love with the bow rudder but I don't know her name! There, I said it. To me it's the sexiest most efficient and effortless move in a kayak. More than that, the way the boat spins under you when motions align just right feels almost magical. The turning momentum seems to perpetuate itself. It's like the boat starts to give back what put into it.

For a decent free skill description and illustrations of the stroke with moving images see this Atlantic Kayak Tours web page. Search also for "Bow Rudder" among these videos by Doug Cooper if you'd like to see a short movie of the skill in action. If you don't have them already Doug Cooper and Gordon Brown's books are great resources for updating your kayaking skills. They both also contain good consistent descriptions of the Bow Rudder. Gordon has a DVD companion to the book out as well.



Gordon Demonstrates cross-bow rudder

Then, there's another detailed and well-illustrated description of the skill by the same name by Derrick Mayoleth. You may not even notice much difference between the two versions but, in my opinion, what separates them is so critical that two different names should be used to label them. Derrick's is the way the bow rudder looked when I met her but she is definitely not the one I fell in love with. Yet, it is the skill as illustrated by Derrick that seems to fit the name. That stroke actually attempts to pull the bow in the direction of the blade. Applying the same name to the turning maneuver presented by Atlantic Tours, Brown and Cooper (ABC) seems to me like a long stretch. More than surface semantics, both of the words in the name obscure the little ABC gem from the sights or well-meaning students of the sport. What's your name, darling?



Derrik demonstrating lean-forward bow rudder


ABC version of the 'so-called' bow rudder is neither done at the bow nor is it really a ruddering stroke. ABC way, the active blade is planted perpendicular to the surface of the water at the paddler's knees, next to the gunwale. The placement is much closer to the kayak's longitudinal center of gravity than its bow. Furthermore, there is really no reason to move it in that direction in principle. If anything, I am curious it if wouldn't work even better applied a foot aft. The live blade placement is distinctly different in the forward-reaching skill as illustrated in Derrick's post. Here the paddler needs to lean distinctly forward and advance the rudder toward the bow. The body rotation in the two versions is in the opposite directions. For ABC you "face the work" on inside of the turn with maximum torso rotation. In the alternative, you are rotated with the opposite shoulder facing the bow as the outboard hand extends as far forward as possible.

The term 'rudder' in the name implies that the paddler should be trying to concentrate the action on the end of the boat. After all, 'rudder' is a steering contraption always found at the (rear) end of the boat. Substituting 'bow' for 'stern' does nothing to the implicit suggestion that the stroke should be performed as far away from the center of the boat as possible. The first term in the name—'bow'—does the same thing: it tells you to reach for the bow with the paddle.



Atlantic Kayak Tours version of bow rudder

The role of the active blade in the ABC incarnation is not intended to move or anchor the bow. Here the paddle in the water serves the role of a pivot point around which the kayak swings–bow moving in one direction stern in the opposite. In that sense, although it is clearly meant for turning the boat, the move feels more like a draw-on-the-move or a side-slip than a rudder. Cooper gives an apt analogy when he writes that bow rudder should feel like a runner grabbing on to a stationary post with one hand and spinning around. The forward-reaching version of the bow rudder emphasizes anchoring the bow, releasing the stern so that it could slide around. Leaning forward, weighing the bow, taking the weight from the stern, and sticking the blade near the bow to anchor it are mobilized to that end. The ABC version treats bow and stern on equal terms. Instead, it capitalizes on finding the most efficient pivot point on which to spin the kayak around its longitudinal center axis not unlike a table-top. The paddler remains fully upright throughout the turn.  Finally, the lower elbow is fully extended in the former and tucked into the pelvis in the latter--seems a bit safer to me.

I am yet to confirm this in the field, but I would guess that the ABC way would not work quite as well as the lean-forward version for turning into the wind. In practice, I only know that I can easily turn 180° or more on calm days but was barely able to do 90° with strong beam wind using ABC. The latter is much more efficient at producing quick radical changes of direction in tight quarters will less body contortion … not to mention it looks much more elegant and also makes your legs shake with excitement J

So what do you think—are these two different versions of the same skill or two different skills? Are we doing those who are learning the skills any favors by misdirecting their attention from the knee toward the bow and toward ruddering instead of pivoting and spinning? How about something like "gunwale swing" or "beam spin" instead? The way the kayak dances alongside the planted blade could almost pass as a dos-รก-dos dance move. Whatever you call it, give them both a try and see if it changes your relationship as much as it did for me. Whatever you decide, I'll always go to my spinning version to get a smile on my face and a tingle in the belly.

While we're at it, how about a cross-bow bow rudder that is initiated by bringing your paddle across the deck rather than the bow, has the blade planted at the cockpit rather than the bow, and uses the paddle as a pivot point rather than a rudder? Any takers?