Will a 15hp plane it with 300lbs of me and my wife?

Discussion in 'Powerboats' started by Tinklespout, Feb 26, 2013.

  1. Tinklespout
    Joined: Oct 2012
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    Location: Fl

    Tinklespout Junior Member

    Princess Marine

    I sure wish that I could find specs on it. I guess that they were only in production for 3 years.

    Kim
     

    Attached Files:

  2. Submarine Tom

    Submarine Tom Previous Member

    Posting pictures is not simple.

    It took me three years to figure it out.

    I believe you're missing one step but I can't describe it.

    Not to worry, one at a time is fine.

    Can you get an estimate on what it weighs?

    A 25 might do but you really need to get a weight.

    You can weigh each corner and add them together.

    It doesn't have to be exact.

    Do you have a gravel, concrete, soil, road scale in your 'hood?

    Just subtract the estimated weight of the trailer...
     
  3. Tinklespout
    Joined: Oct 2012
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    Location: Fl

    Tinklespout Junior Member

    Princess Marine 14foot 11 inches.

    I will have to weigh it I guess. I was told these boats were plentiful but I guess that's just what an anxious seller tells you. She said they planed it off with a 10hp. She seems like a truthful type. I've followed some hull design discussions on this site and have seen situations where hull designs can do this but they were long, narrow and flat. I'm wondering if there is some lift generated where the tunnel meets the flatter part of the hull towards the back.

    Bottom line is I will have to put the motor on and try. Seems that some of the comments here would warrant the effort. I've not heard "forget it, stupid".

    Kim
     

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  4. Tinklespout
    Joined: Oct 2012
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    Tinklespout Junior Member

    Quick explanation

    Just wanted to thank you all for being so helpful. The reason that I am being particular here is that I have some limitations right now.

    o) towing with a Mini Cooper, 1400 pound limit
    o) have a nice newer 15hp, 4-stroke Yamaha and associated steering, etc
    o) 15 hp is limitation in some lakes here
    o) I want enough boat in case some chop kicks up in Charlotte Harbor and Boca Grand. They can be a bit intimidating.
     
  5. Manie B
    Joined: Sep 2006
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    Manie B Senior Member

    You need at least a 30hp (max 50hp to fly)
    nice boat - fix her up and you will have fun
     
  6. Manie B
    Joined: Sep 2006
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    Location: Cape Town South Africa

    Manie B Senior Member

    You can post many pics on a post
    just upload them one at a time

    click -
    manage attachments
    browse
    upload
    browse
    upload

    submit reply
     
  7. BMcF
    Joined: Mar 2007
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    Location: Maryland

    BMcF Senior Member

    That looks strikingly similar to Woody Woodson's boats. I have two of his Cathedral 18s..a 1964 and a 1968.

    I also have a Whaler 15', 1974 model.

    The short answer is simply no. I would guess that you would need something around 35HP to reliably plane that hull..or even more. That said, you have to realize that such hulls have a hump in drag curve..a pretty big one..so you could cruise along at 15 knots and better, once on plane, at less HP. But you need the bigger engine to get you there.
     
  8. Tinklespout
    Joined: Oct 2012
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    Tinklespout Junior Member

    Ok, I give up!! THANKS for your knowledge. Hope I can return the favor sometime.

    Y'all (proper english: Everyone),

    Thanks so much for all of your honest feedback. I love these forums for this very reason!

    If anyone is in the Port Charlotte FL area and knows someone who might be interested in this boat just let me know and I'll put you in touch with the owner. She has put a lot of effort into it but needs a lighter boat because of some back problems. She's not asking much for it.

    I'm back to my quest for a lighter boat since I need to stay with the 15 hp. Lots of areas here have this as a motor size limitation. Plus, its real quiet and finally my poor little Mini Cooper is limited to a little over 1000 pounds; 1400 actually but I don't like to push the limit.

    A 1954 16 foot Lyman just hit the market here. Its always been a dream of mine to have a classic mahogany boat to sand and polish so PLEASE don't tell me it won't work, unless of course you believe it to be true.
    Thoughts on the Lyman??

    Thanks again.

    Kim
     
    Last edited: Feb 28, 2013
  9. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Kim, I think you can get the boat to plane with 15 hp with your wife sitting on the bow and yourself in the center.
    I gave a holiday guest a piece of aluminum tube so he could sit further away from the outboard engine. He alone had almost 300 lbs and plowed through my bay in an inflatable, the bow pointing at the moon. With the 2 ft. tube over the tiller the boat got over the hump and he could move back to the stern with the boat planing at full throttle.
     
  10. hoytedow
    Joined: Sep 2009
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    hoytedow Wood Butcher

    The old Sportabout made by Folbot would plane with a 15 hp and 2 adults aboard. I built one from a kit and loved the way it performed, even though I lengthened it during construction from the original plans to 15' 9". Of all the boats I built, I think it was my favorite.

    I can't find my old photos of my own but the hull shape is shown below.

    http://folbot.wordpress.com/

    [​IMG]

    [​IMG]
     
  11. BMcF
    Joined: Mar 2007
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    BMcF Senior Member

    I had a very small Carolina skiff (12'?..don't remember exactly) that would plane out with only 10HP and with two people in it..as long as one of those two got as far up front as possible when getting the boat to plane. The key there is, small, light and a flat bottom.
     
  12. johneck
    Joined: Nov 2011
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    johneck Senior Member

    Is that a 15 hp trolling motor Hoyt? Just kidding; nice boat though. Looks like it was made to push easily at low speeds.

    The trihulls do take alot to get on a plane, there is more wetted surface than really needed. I seriously doubt it will plane with 15 unless you get out the sawzall and do some weight reduction surgery.
     
  13. hoytedow
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    hoytedow Wood Butcher

    My boat had a 15 hp Sea King(Montgomery Ward) motor. The boat in the pictures is not my boat, but the same design, except I built mine a foot longer in 1973.
     
  14. tunnels

    tunnels Previous Member

    On a boat that size i wouldnt want to be seen leaving the shelter of my garage if it didint have ast least a 50 hp motor !! :idea:
    15 hp on the back of a 10 foot tinny is exciting !!!! :eek:
     

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

    That's not going to plane with a 15 HP outboard. I'll bet you're looking to push about 1,500 pounds with a small crew, fuel tank, battery and 15 HP (and I'm being generous), so you'll get about 13 MPH, maybe 14, which isn't up on plane. There's a lot of drag associated with that hull type, so you'll want at least a 25 HP, which will get you to about 19 MPH, which is on plane (just barely), but you'll get knocked off, with the first bit of chop you encounter, so consider a 30 HP as a minimum.
     
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