Boat buidler/designer seeking advice on design

Discussion in 'Boat Design' started by DownRiver, Feb 18, 2010.

  1. DownRiver
    Joined: Feb 2010
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Idaho

    DownRiver New Member

    Hello, I am a small drift boat builder out in Swan Valley, Idaho. We primarily build drift boats designed for an oarsman and two passengers to row/float down stream and fish out of. Since the downtourn of the economy I have had plenty of time to research and start a new design based off of our first boats.

    As I am sure builder/designer knows everyone is a critic and everyone has a better idea, it is our job to come up with a design that everyone can agree works and adds innovation as well as safety. For many years drift boat design has been stagnate which is why I decided to test the waters so to speak. Manufacturers have tended to just rely on the status quo to get by and haven't really tried to think outside the box to expand their market. When I put my boat into the marketplace the industry reacted very adversly due to the fact I had just shook up design as well as the material aspect of the drift boat. My boat wasn't built out of fiberglass, aluminum, wood, it was all composite with a foam core, carbon fiber, and a polyurethane exterior. Most said it would not float, when it did they said it must weigh a ton, it was lighter. What they could say is that my bottom design was untested.

    Traditional drift boats are built with a flat bottom that incorporated rocker at the bow and the stern. Some builders have gone as far as to put a tunnel from the stearn to the middle of the bottom, and another used a very light material for the boat which allows the bottom to raise in the water making it concave. I looked at what a the boat is supposed to do for me. I need to be able to hold the boat in place, row back upstream in reverse, and crab walk the boat sideways. The stearn of all drift boats is essentially an upside down trialngle with the point cut off, so if your rowing upsteam or holding the boat in place against the current the stearn could create a wall of water making it hard to row against. I added more rocker than anyone else to allow the water a seamless flow under the boat making it easier to manuever. Next, I created a tunnel/funnel starting where the water actually met the bottom of the boat. This, in theory, was desinged to channel some of the flow into to funnel which speed up the flow creating turbidity and lift. In theory this should allow the boat to ride higher due to lift and allow the boat to hold in place easier and row back better. Like I said in theory. I also added to six inches to the bottom beam width and a foot to the overall beam width. So with a wider bottom boat it is more stable, and I flared the sides out to add more stablity due to the fact that people walk around in these boats and they are only 8 feet wide and in addition I used a softer chine to allow the boat to slide up and over obstacles as well as for seemless flow.

    So my questions are these; I have had a mixed bag as far as people saying the boat rowed easier due to my technology, some said it depends on water conditions, some said it was better hands down. I have had people agree with what Ive said but they rowed the boat and would stick with the other boats because the are narrower and seem to be faster reacting than my wider boat. I am seekeing advise on how to build this boat narrower while not lossing stability and also what you think as far as bottom design, remeber these are very shallow drafting boats due to water depth. How do I create a better tracking bottom that doesn't seem to grab in certain water conditions? Do I use smoother lines for my tunnel, do I widen the tunnel? The goal is to stay strait in current until you ask it to manuever sideways with an oarstroke.

    I believe in my design, although I have been second guessing myself with so much downtime. Also I just put the boat into Deftship and I can't seemed to create the chine on the bottom of the boat, any ideas. Sorry for the lengthy post, I figured it to be easier to reply with some history. Here are some pics of the boats.

    Attached Files:

  2. Guest625101138

    Guest625101138 Previous Member

    There is an <Edge> <Crease> tool on the menu bar that allows you to crease the hull along the selected line on the control net.

    Some detail on the actual shape might enable more informed reply on the stability.

    Also if you do something that accelerates flow under the hull it will lower pressure and cause the boat to squat not lift.

    Rick W
    1 person likes this.
  3. McCormickDesign
    Joined: Feb 2010
    Posts: 24
    Likes: 1, Points: 0, Legacy Rep: 10
    Location: Auckland, New Zealand

    McCormickDesign Draftsman - 3D modeller

    You may want to ask/email John Wellsford, he is a small craft builder from NZ and i'm pretty sure he has designed a few flat bottomed boats similar to the image.
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