Side pods

Discussion in 'Boat Design' started by Saqa, Nov 30, 2013.

  1. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Hey guys, any examples of boats with side pods? Something like outrigger concept but close in mounted directly to the boat to increase beam and stability? I am thinking about a adding a removable pair to the boat I am making to open up a bit more fishing options
     
  2. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    I made a narrow boat with a waterline max beam of 1.2m and total length of 4.3m. I made it narrow as I will be spending a lot of time trolling lures by rowing. I made 8' oars for it.

    But I am thinking that it will limit some fishing options such as standup casting and such on trips dedicated to that. What I am wondering about in the question above are a pair of ply pods slotted to the boat sides but I also have one of these that will now just be sitting around rotting
    http://www.sevylor.com/Coloradotrad...l-P2037.aspx?gclid=CI3LoI20jLsCFYWDQgodIz8AvQ

    I am wondering about taking of the tubes and attaching them to my boat. In a manner where I can deflate them and take them off and store under the deck
     
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 7,944
    Likes: 341, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

  4. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 114, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    [​IMG]


    Sponson it the term for monhulls
     
  5. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Yup, thems the types. The Airofloat type I can make by cutting out the sponsons from the colorado and attaching it to the boat. Would make for the simplest implementation or I can make something like the boat collar with ply with all the work and expense that goes with it

    Looking for opinions on both systems, pros and cons. I think I would go the ply pod route if the performance gains over the tubes are significantly higher
     
  6. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

  7. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 114, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    You wont be happy with sponsons...they slow the boat and cause the boat to pound terribly.
    This is why a RIB has such a kidney destroying ride...t
     
  8. daiquiri
    Joined: May 2004
    Posts: 5,372
    Likes: 239, Points: 73, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    One compromise solution could be to keep the sponsons above the waterline. In that way they start working only when the boat is heeled by a good angle.
    The spanish boat in your last picture seem to use that principle. Those triangular-section sponsons have most of the volume up above the waterline, thus imo only slightly increasing drag in the upright position but considerably increasing the stability at (approximately) 30+ degrees of heel.
    Cheers
     
  9. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    I am thinking along similar lines. About adjusting fitting height so that they only in contact with water when at rest
     
  10. Squidly-Diddly
    Joined: Sep 2007
    Posts: 1,477
    Likes: 57, Points: 48, Legacy Rep: 304
    Location: SF bay

    Squidly-Diddly Senior Member

    I was toying with idea of adding a ring of 'pool noodles' under the overhanging gunnels of an older fiberglass rowing shell.

    They would be clear of the water, just barely.

    I've seen molded add ons on canoes, mostly for 'rental market'.
     
  11. messabout
    Joined: Jan 2006
    Posts: 2,996
    Likes: 199, Points: 63, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    A small boat with a chine beam of 1.2 meters is sufficiently stable to allow standup fishing. That is particularly true of a boat with hard chines. No need to complicate a nice little boat with gimmickry.

    These comments are time tested but apply only to fishermen who practice sobriety while afloat.
     
  12. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Hi mate, I was told the opposite when I started working on this boat. That it will do some sort of crazy chine slide or such being so narrow if used for standup fishing

    This is why I am considering sponsons
     
  13. messabout
    Joined: Jan 2006
    Posts: 2,996
    Likes: 199, Points: 63, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Saqa. I have no quarrell with some sort of sponson setup for ultimate righting moment. They will, however, make the boat heavier and more unhandy to load and unload, in addition to extra construction time and detail. Viewing the picture above, it is clear that the boat will have to heel a considerable distance before the sponsons take affect. To take advantage of the sponsons for initial stability, position them such that they are always in the water. If that is to be, then you have a sort of trimaran. Why not just make the boat a little wider in the first place and leave the sponsons on the drawing board? Roughly speaking, the cube of chine widths can be used as an estimate of relative initial stability.

    When I suggested that 1.2 meter chine beam is sufficient, I was speaking from experience not opinion. My flat bottomed skiff is 4.7m long x 1.3 at the sheer and 0.95 at the chine. I stand up and walk around with reasonable assurance that I will not be tossed into the drink. The boat also has a sail of about 8 m^2. The boat is sufficiently stable under sail in 15 to 20 knots of breeze.

    If your boat has 1.2m chine width and is flat bottomed and hard chined, it will have something like twice the initial stability as my skinnier boat. One point two meters is the defacto bottom width for simple fishing boats here in the US. That's because it is the width of a sheet of standard plywood. Countless thousands of small fishing boats have been built to that dimension. They are a bit too wide to row well but 48 inches (1.2m) is a perfectly good compromise.
     

  14. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Ok mate, thank you for that info. I guess I will find out how she behaves once she is on the water. The sponsons I am in favor of are the ones I would take off my colarado and would be just a simple add on later on if needed
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.