Sealution kayak doesn't track straight--tends to veer off

Discussion in 'Gear Talk' started by paddlin-tom, Jul 21, 2019.

  1. paddlin-tom

    paddlin-tom New Member

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    Hi,

    I have an older poly Sealution kayak. It is 16.5 feet long and 22.5 inches at the center. I've paddled it for years, but only after paddling my friend's current designs kayak for a comparision, I realized my kayak tends to veer off if I stop paddling. It is kinda like trying to push a grocery cart backwards vs. forwards. As the kayak starts to go off track, it will go more and more off track until I'm facing backwards. It happens to both sides and needs no wind. I think this might be due to the very long front end of my kayak, such that my weight is actually rather aft. It reminds me of how the balance on an airplane needs the center of gravity ahead of the center of lift for the plane to be stable. As they say, "a tail heavy plane only flies once." And for a kayak, it means I'm constantly making correction strokes to keep it straight--I can't pause or I'll start to very off. I'm wondering if I can either add weight to the front, a skeg/rudder to the back, or maybe its just how the boat is. A long while ago I read a review of the sealution which mentioned that they don't track very well--maybe this is why. Thanks for your thoughts, suggestions, ideas.

    T
     
  2. mick_allen

    mick_allen Paddler & Moderator

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    You could carry a little gear or weight in the back but I would take it as a point of pride not to have a straight tracker unless it was really useful to you. Any symmetrically shaped boat will do the same as above where going forward or backward, no big deal.
    So what if you do have to paddle backward in a straight tracker - it'll drive you nuts - so I think it is far more interesting to have one that behaves similarly in either direction. For certain your skills will increase. I think one of my short boats will almost 360 with one stroke.
    But if it drives you crazy, just add weight [edited to add: in the back- just saw John's post below] - or g-flex on the most minimal skeg strip that you can stand.
     
    Last edited: Jul 22, 2019
  3. JohnAbercrombie

    JohnAbercrombie Paddler

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    I think that 'oversteering' is usually made worse by weight forward (which I think is what Mick is saying).
    You could do some experiments with weights added to the stern (or bow) to see how it affects the boat handling.
    Some soft water containers would do as they don't slide around too easily.

    Some years ago I had an email exchange with Bjorn Thomasson when I was working on my Frej kayak. I wanted to move the seat forward to fit better under the thigh braces in the keyhole cockpit. Here's part of what Bjorn said:
    You may end up with the lateral center of gravity forward of the lateral center of buoyancy, which must be avoided in a rudderless kayak. Such forward tilt may increase flatwater speed slightly (and is thus favored in racing kayaks and, to some extent surfskis) but will play havoc with directional control (over-steering in automotive terms). With the LCG aft of the LCB the kayak becomes easily controlled with predictable movements (slight understeering). Small errors in the LCG/LCB configuration can be quite easily compensated by moving a water bottle/bag and other heavy items forward or aft until the kayak behaves the way it is supposed to, but too much may make paddling unnecessarily challenging.
     
    Last edited: Jul 22, 2019
  4. Roy222

    Roy222 Paddler

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    Mr. T ( or maybe Tom)
    Your airplane analogy was spot on as the center of wind pressure also comes into play.
    It sounds like you and your Kayak are in perfect dynamic balance. If you do not have to over steer into the wind your kayak is in balance.
    Keeping with your airplane theme you could add a small tail at the stern. That would shift the wind pressure balance behind the CG and turn the kayak into the wind. Might be fun to try.


    Roy
     
  5. JohnAbercrombie

    JohnAbercrombie Paddler

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    Tom: Is this your boat?
    mini-Sealution II.JPG
     
  6. Peter-CKM

    Peter-CKM Paddler

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    I don't know that boat, but in general a boat with more rocker will track less well (turn more easily, including on its own when you stop paddling).

    I recently helped out one shop I work for by going through and cataloging their kayaks (they have many different brands and models which they acquired over the past 30+ years) and listed such things as what size paddlers they are good for, what size skirt to use, etc. In doing so, I talked wit some old timers who explained that the Necky Eskia is a high rocker boat and they didn't like using t because it didn't track well and they would have to work to keep it going straight, including when they stopped paddling and let it drift. That explained a lot about why I liked that boat over say a Looksha IV, which tracked better (I like maneuverable boats when I am guiding/teaching).
     
  7. paddlin-tom

    paddlin-tom New Member

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    Thank you Mick, John, Roy, and Peter. That is indeed the boat John.

    And, yes, its really not too dire. I've been paddling with it as is for nearly 20 years. It was only after trying someone else's boat that I started to get annoyed by the tracking instability of my boat. That current designs boat I tried was so effortless...

    I had not heard of g-flex, so I'm going to give that a try. I'll try taping on a temporary skeg before doe that. And I'll surely try putting a water bottle in the back (and front for comparison). Those are both great suggestions. Thank you.

    I greatly appreciate John's recollection of his conversation with Bjorn Thomasson. I hope that by researching some of the terminology he mentioned (lateral center of gravity & lateral center of boyancy) I will be able to figure out the physics of it and make an informed correction by moving a bit of weight (sounds like back is suggested).

    And about rocker: This boat probably has more rocker than when original. Its an old boat and has sagged some even though I try to rotate it and support it well. So Peter might be on to something.

    And about the wind: The boat does pretty good in the wind. I have no complaints there, and performance in the wind is probably more important than flat water tracking, so I appreciate Roy's thought on that.

    Again, thank you, thank you. Very helpful discussion by all.

    Happy paddling,
    Mr. T (haha)
     
  8. JohnAbercrombie

    JohnAbercrombie Paddler

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    I think a 10L Dromedary (or two) or a few 'wine bags' of water were what Bjorn suggested - i.e. 10+kg vs 1 kg.

    A friend stops when it gets windy and loads some rocks into his Seda Glider - any weight will do!
     
  9. chodups

    chodups Paddler

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    I was in a kayak shop years back where the operator hung all boats from lines attached to the end toggles. Glass or plastic it didn't seem to matter. During the course of the paddling season one particular rotomolded boat didn't sell and hung for months. Eventually it changed shape to a banana. People look at my Progression and scratch their heads but this boat was so far beyond that and was totally unsellable.

    How does the rocker present when you set it on the floor?