Newbie on board, first post, first question!

Discussion in 'Stability' started by Aperfectimperfe, Aug 22, 2012.

  1. Aperfectimperfe
    Joined: Aug 2012
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    Location: South Africa

    Aperfectimperfe New Member

    Hi all,

    From scanning through the posts on this board it seems I'm in the right place for assistance - although most posts seem way above my head!

    I have a quite common problem in a specific aspect of stability that I'd like your input in.

    I am one of the crazy South African sea kayak fishermen that braves the Indian ocean with great whites and makos snapping at our heels in a skinny boat with just a paddle for propulsion.

    This means that stability is a big deal. The faster kayaks are rather long and thin for better efficiency and my current one is 5m long by 0.55m wide with a water depth of about 90mm. It is fast and I love it. When paddling stability really isn't an issue - that can be fixed by a paddle stroke.

    Where the problem comes in is when stationary. The hull is very rounded and length to breadth ratio is not very favourable. This is made worse when fighting a fish - the length of the fishing rod acts as a lever and makes tipping over sideways a very real possibility.

    What I have found on the 'net are an array of pontoon solutions which really don't work for this application, beach launches are typically through 6 foot waves and any outriggers will mean a nasty end to any attempt!

    What I have considered is a fold-able skeg mounted directly underneath the boat, which can be deployed when needed and retracted when paddling to reduce drag and increase turning circle. My idea is a simple 500x500mm fin which should give enough resistance to tipping - sure it won't stop a roll if the centre of gravity is permanently off centre, but will provide some sort of leeway to the transient pulls of a large fish sideways (if you know what I mean)

    Has anyone got comments or ideas that can be used to develop this?

    Thannks,
    Mark
     
  2. hoytedow
    Joined: Sep 2009
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    Location: North of Cuba

    hoytedow Wood Butcher

    You need a bigger boat.



    Oops! I forgot to welcome you! Welcome!
     
    Last edited: Aug 23, 2012
  3. Frosty

    Frosty Previous Member

    Well done Hoyt you nailed it there.
     
  4. Aperfectimperfe
    Joined: Aug 2012
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    Location: South Africa

    Aperfectimperfe New Member

    Bigger boats are for softies.....
     
  5. J Feenstra
    Joined: Jan 2012
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    Location: The Netherlands

    J Feenstra Junior Member

    A lot to learn from this discussion!
     
  6. Frosty

    Frosty Previous Member

    Buy big , live longer.
     
  7. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A skeg, folding or other wise isn't going to make an appreciable difference in your boat. It will not affect stability at all and as to lateral area, sure a very modest amount of resistance, mostly token, could be expected. If a fish, even a large one is affect your boat, obviously you need a bigger boat (just like in the movie).
     
  8. Frosty

    Frosty Previous Member

    Nice to have met you.
     
  9. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    I had this idea, and I welcome anyone to criticize it.
    I imagine you carrying a couple of foam blocks (glued up of lifts of thinner foam if necessary). About 300mm cubes should be adaquate (or the same cubic capacity but a flatter dimension if desired) with an (approx.) 20mm x 100cm aluminum pole, the ends of which are set (glued and fastened) into the blocks and are inserted into a hole in each side of the cockpit side (outside) where you can easily reach them to connect and disconnect and the sockets don't interfere with your cockpit seating space.

    Then you make flush sealed sockets about 100mm deep behind those holes, well reinforced within to prevent leverage from causing breakage. Lastly, tether them together with a bungee to cause them to be pulled inward and stay attached, which will make it easy to remove them as well.
    If the sockets are placed well above the waterline and angled downward a bit, they won't be a disaster if they accidentally break.
    The system would work well if the foam blocks were mostly if not completely submerged when the kayak is loaded with your weight. You can tip the kayak while inserting them.
    This should all cost next to nothing but would require some skill in fabricating. Correctly done, you should be able to fish standing up in smooth water.
     
  10. Petros
    Joined: Oct 2007
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    Petros Senior Member

    mark, not really possible to make a fast slim kayak also a stable fishing platform.

    a skag will not imrpove stablity, you need outriggers. but here is the way to make them work, use your spare paddle with inflatable blade covers, and bungee them to your deck when you go fishing.

    so you paddle out in 'clean' configuration, when you get to your fishing spot you inflate the paddle floats, slip them over the paddle blades and bungee the paddle down across the foredeck of the kayak. Now you are in "fishing mode".

    Once you land the big ones, and they are safely stowed below deck, you remove the paddle outriggers and paddle back to shore.

    I would use a spare paddle so you will have your main paddle available for moving around.

    Good luck.
     
  11. Frosty

    Frosty Previous Member

    Good luck indeed but I suggest you instruct the crew to cover the fish with crushed ice before stowing below deck and steaming back to market.

    I believe a good quality 400lb Tuna can bring 1/2 million dollars.
     
  12. hoytedow
    Joined: Sep 2009
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    hoytedow Wood Butcher

    Would a 1/5 ton Tuna fetch as much? ;)
     
  13. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Stable Kayak - split stern

    How about this for built in stability without nuisance outriggers and other gear.


     
  14. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    How much is that a liter? A 1/2 million dollars? What is that? Does a 400lb tuna sink a small kayak as fast as a 181.436948kg tuna? Is a large tuna weighing 1814.36948dg even going to fit in a 55 X 500 centimeter kayak? It must be almost 947 1/16s of an inch long. ? After steaming back to market, how do you describe the stink in metrics? Odorectares or smelogrades or something?

    To the OP, maybe you can add flare to the kayak that only comes into play when the boat is leaned.

    A large portion of the kayak outriggers on google images fold in out of the way for when you want, like launching from a beach.
     

  15. hoytedow
    Joined: Sep 2009
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    Location: North of Cuba

    hoytedow Wood Butcher

    You could add a large cast iron keel.
     
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