Dorado 30 High speed stability

Discussion in 'Powerboats' started by Austin, Apr 24, 2020.

  1. tonipu
    Joined: Dec 2014
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    Location: croatia

    tonipu Senior Member

    hi, i see a litlte beet keel in the bow if i noticed well, maybe 2inch deep, when my friend added a little bit keel to a fjord 25, it becomes a very unstable boat, and heve a big tendency to broaching, sometimes when we encounter a small wave, the boat go to one side and we must slowe down.
    then he cut again the little keel he added, and the boat became stable again.
    the keel was only 1 inch starting from the bow in the front, and maybe 4 inch on the aft
     
  2. tonipu
    Joined: Dec 2014
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    Location: croatia

    tonipu Senior Member

    Keel photo, he added because of low speed fishing, and it was better for low speed troling
     

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  3. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    tonipu, it is a bit surprising that addition you pictured, would tend to broaching, you'd think it would be neutral at worst. Unless it isn't quite what he added ?
     
  4. tonipu
    Joined: Dec 2014
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    Location: croatia

    tonipu Senior Member

    Yes he add the small keel, the boat was incotrolable in litle folowing sea.
    Tomorow i Will picture the boat, now original without keel
     
  5. tonipu
    Joined: Dec 2014
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    Location: croatia

    tonipu Senior Member

    As i promise picture of a keel he add on his fjord, an picture of the boat now when keel was removed
     

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  6. Austin
    Joined: Apr 2020
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    Location: FL

    Austin Junior Member

    Just updating the thread.

    still have the same results. The boat handles best at speeds under 28mph. It will run faster but requires a lot of steering input and constant attention.

    Not really surprised as the boat was designed with a 200hp inboard diesel. Having 400hp is just overkill.
     
  7. Austin
    Joined: Apr 2020
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    Location: FL

    Austin Junior Member

    Another update. I filled the fuel tank which is close to 220 gallons and the boat rides handles much better at speed. It was able to cruise 35mph in 1 foot chop with a quartering wind with no issues.

    I’m assuming the added weight low in the hull lowered the CG and puts more of the hull in the water moving the Center of Pressure (not sure that is called for a boat hull) to a better spot.

    the boat drafts a little bit more but I will be keeping the tank full from now on.

    thanks for all the help.
     

  8. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    That is a monster tank, it has probably put more forward portions of the boat in the water consistently, and presenting a different "face" to the water. Pleasing to get at least an improvement, good luck with it.
     
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