Pontoon Design

Discussion in 'Boat Design' started by CraigCat Sam, Dec 11, 2016.

  1. CraigCat Sam
    Joined: Dec 2016
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    Location: Marietta, Ga

    CraigCat Sam New Member

    Can anyone access the likely navigational performance of a 30 foot pontoon boat (17" pontoons) where a 30 HP outboard is positioned in the middle of the deck approximately 10' from bow . This is a strange configuration but I have a valid purpose and would like to know what experienced designers think the steering effects might be. Any help appreciated. :idea::idea:
  2. Poida
    Joined: Apr 2006
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    Poida Senior Member

    I did put an outboard on the frame of a surfcat. It didn't steer, it carried on in the same direction, sideways.

    This is because I was using the outboard to steer.

    If I had kept the outboard rigid and steered with rudders on the stern of the hulls, it may have worked.

  3. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    If your engine is one-third of the way aft of the bow, and it is more or less level trim, chances are it will still steer, weakly, but opposite to what would happen if it was at the stern. If the bows dip, though, you could be just crabbing along like Poida says.

  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Get the outboard as close to the bow or the stern as practical for best steering response. The bow mount has obvious disadvantages and some not so obvious, but I've seen mooring tenders setup this way. You're not going to want to go very fast, but with a several hundred pounds of mooring block dangling from the hoist, speed isn't typically a concern, compaired to just moving them. I've seen some gill netters rigged this way too, but generally any vectored thrust drive, needs to be as far from the boat's natural pivot point (usually near midship at displacement speeds), for best steering response.
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