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Wednesday, May 19, 2010

The wind going round and round.

UPDATED WITH VIDEO 5/19/2010

It seems the kayaking blogging world is having some trouble with wind lately. It is keeping some ashore, and some are venturing out, to explore, and play with the unseen partner we paddle with, but rarely think about. The only exception being if there is too much of it when we want to be on the water. Today I joined the club - though it had kept my trip from happening two weeks ago- as I got to my little lake where I paddle when I am alone, it was blowing at a good 20 to 25 knots. I knew this because the Beaufort scale states that 'Larger tree branches are moving, Umbrellas are problematic' which I was observing. I also had consistent whitecaps, but the waves were pretty small, and that's because I was in a narrow V shaped lake, which didn't give the wind much 'fetch' to effect the water. (Fetch is defined as The distance over which the wind can blow unobstructed by land before reaching the observer.) The longer the fetch, the bigger the wind, as well as the bigger the effects of those winds on the water. I decided to again play with the wind to study how my boat reacts, I cut across the wind, so it came to my left (or port) side, at about a 45º angle. Sure enough my kayak acted as I expected. It wanted to turn into the wind, or weathercock to the left. I corrected this first by putting a bit of edge into my boat, I leaned to the left, which 'unlocked the bow' and induced a slight turn keeping me on course. But I wanted to experiment with other ways to do this. My next method was to add a bit of a sweep on the end of my forward stroke on my left side. This worked as well, and as I expected. The next method I tried was to slide the paddle shaft in my hands just slightly to the left, and continue with a forward stroke. I moved the paddle about 3 inches off center, this provided stronger force on the left side than the right, which added just a bit of turn. This method is simple and effective. It doesn't require any particular skill or balance. Yet I rarely see people employ it. If you paddle all day in a wind pushing your kayak in a particular direction it is highly effective.

I turned my kayak 90º to the left, thereby putting the wind on my right side at a 45º angle, and tried all three of these fixes for a wind creating a weathercock. I was pleased to see that all of them worked as expected, and I was comfortable doing all three on both sides.

It's important to understand that the weathercock was happening, because the bow of my kayak was locked into the water with it's deep V shape. The stern doesn't lock in quite as much, and so the wind is able to push the stern, when the stern is pushed, it swings the nose into the wind.

I rounded a small island, paddling through the lee of the island where the land blocked the wind, I circled to the windy side, and noticed that leaves had collected in a small recirculating section of water near the other end of the island. I knew I could stop there with no fear of being blown out of the spot. When leaves, or kelp, or foam collect in an area, this is a spot that is protected from wind and current. A good spot to rest or observe. I chose to observe. I pulled into the spot, and with one quick reverse stroke, stopped my forward momentum. I sat and watched the water, and the way the wind was effecting it. I realized I was just a few feet from a very noticeable wind line. I knew that if I was just a few feet to the right I would feel the effects of the wind. So I did a sculling draw, and when I hit the wind line I felt the immediate push of the wind, now behind me. I quickly unfeathered my paddle, and continued on, This time with the following sea. I noticed, this time to my surprise that the wind and water behind me made my kayak want to Lee cock. Lee cocking is the reverse of weather cocking. Instead of my kayak turning into the wind, it wanted to push the rear out to the side, forcing the kayak flat to the wind. Because, again, the stern isn't as locked to the water as the bow. The simple fix for this is to lower my rudder - or a skeg if you have one. I chose not to do this, for two reasons, first, I wanted the experience of paddling in the following sea without it. I wanted to be forced to make the corrections with my paddle and body. This practice will make me a stronger paddler. The second, I had failed to remove the little bungee that locks the rudder in place, making it almost impossible to lower the rudder. I could have reached back, and unlocked it with the tip of my paddle were I in dire straights, but as I said I chose to paddle with it up anyway. Add this to the list of reasons why people prefer a skeg over a rudder! I continued back to my put in, this time aided by the wind, it was a very short trip. I toyed with doing a couple of rolls, but decided against it for various reasons. perhaps next time.

In the video, watch the tops of the trees in the back of parking lot. the constant moving grass, and the branches near the car. Then You will see me shifting the paddle first left, then right. to maintain a course.

NOTE: I just noticed that I never attached the video for this post, so I am updating it here. I was thinking that it was interesting the posts that get the most comments, and the most video views are edging and wind related. I think I am recognizing a trend. Do you - Yes, I am talking to YOU! - think this is an area of general confusion, or concern? What are your thoughts?


wind 2 from Paddling Otaku on Vimeo.

6 comments:

  1. A subject of interest to all of us, PO. As I read your posting I realized that part of the pleasure of our last paddle was that we enjoyed impressive waves...but very little actual wind. As you saw in the images in the posting on our blog, we could "hide out" in the troughs of the waves but the brisk wind I referred to in the narrative had, in fact, subsided soon after we launched. What we played in was the residual "swell", the result of the aforementioned "wind-generated" waves created earlier up the Strait of Georgia. There's significant fetch here so the wind that had been blowing gave the waves a pretty good kick-off. It was the best of both worlds! Gotta love this stuff! Thanks PO. Duncan.

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  2. PO, one thing about edging:
    I have been told that edging a kayak changes the shape of the hull that is submerged and forces the kayak to turn when underway (edged shape becoming asymmetrical).
    You describe that the edging of the kayak unlocks the bow and makes it drift downwind.
    Would the kayak drift downwind even if you were stationary?
    One more thing: don't underestimate the resistance a retracted rudder (on deck) has, causing weathercocking.
    One of my kayaks, when the kayak was used with the rudder retracted, would track neutral in beam winds (no lee or weather cocking).
    I later removed the rudder assembly and suddenly the kayak was leecocking.
    Long story short, I eventually modified the hull to avoid leecocking...

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  3. Yes, Gnarlydog, it would. without the V shape of the bow vertical in the water, there is less resistance to the wind and the boat will drift. SImilarly if the boat isn't moving the bow isn't having as much effect, though I will confess now that we are getting into the realm of nautical engineering that is beyond me.

    I am surprised that the rudder on the deck had so much effect, and I wonder if there wasn't something else in play in that situation. Think about the size of the stowed rudder on the deck, compared to the size of you - the paddlers body makes a great sail - or even the size of the side -gunwale- of the kayak. Both much bigger. Interesting though. I wonder exactly what was going on.

    thanks, as always you make me think very hard!

    PO

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  4. Dang, you made me think too now, PO.
    OK, next time I'm out on the water and it's windy I will do exactly this:
    1) paddle in a beam wind and (not using the skeg) edge the kayak (leaning gunnel into the wind) to allegedly release the bow and make it lee cock
    2) paddle and edge the kayak away from the wind (gunnel up, away from the wind, which should still release the bow) and see if the kayak also leecocks
    3) not paddle and not edge and see if the kayak leecocks while stationary
    If your theory of edging to release the bow is correct the kayak should in case 1) and 2) leecock and in case 3) be neutral (?).
    I will let you know of my findings.
    About the rudder on deck: it offers some wind resistance but less than my body.
    However my body is positioned centrally at the pivot point while the rudder is at the extremity where it can make the kayak weathercock (pushing the stern downwind).

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  5. Just for clarity sake, when I say unlocking the bow, I am still agreeing with you that what we are doing is changing the shape of the boat at the water line. We also happen to be angling the sharp V bow so that it can't hold water as well. That is what I mean by unlocking the bow.

    In the first post I did on wind I have video of the my kayak stationary starting bow into the wind, and you can watch it turning perpindicular to the wind. which is the #3 experiment.

    1) if the boat is already sideways to the wind it -beam to the wind, unless I am miss understanding you - it cant leecock because it is already sideways to the wind.

    2) is questionable. if your paddling forward, and edge in part you're going to have an edge induced turn, some of it may be wind. Having not paddled your boat we wont know (or I wont) if it is edge or wind, I would think it will be a bit of both.

    here is a question for you, when you paddle forward, and edge by lifting your right knee, so the right side of your kayak raises. Does your kayak go forward, right, or left?

    I think you and I may need to paddle together, Where are you again?

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  6. PO,
    you are welcome to come and visit me and we will go for a paddle (or two) together.
    All you have to do is buy a ticket to Australia and I will fetch you from the airport, make you welcome at my place and even hook you up with a decent sea kayak (unfortunately no rudder though :-).
    I hear that you like camping; so do I. Can do a trip of a few days or more, if you wish.
    I have enough stuff to fully outfit you (and some) with all camping gear.
    Think of it... when the weather turns cold again and your waters might freeze over my ocean is warm enough to never have to use a dry suit. All you need is a paddling jacket in the middle of winter (July and August).
    What do you think?
    Then again, I just purchased a Folbot Cooper… maybe I could travel…
    US and A is not unfamiliar to me (I lived there for 7 years: MA, VA, UT and finally CA, for 3 years)

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