Adding a small keel or type of skeg.

Discussion in 'Powerboats' started by supremei, Sep 12, 2012.

  1. supremei
    Joined: Sep 2012
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    supremei New Member

    Hello everyone, new to the forum. This might be a crazy question, but I have a 77 Crestliner Aluminum boat 22', inboard outboard for power. I gutted it and made a pilot house boat all aluminum. She rides real nice, but at docking well sometime she has a mind of her own, with a little wind. So I was thinking about adding a short narrow keel maybe 5" down along the existing keel or aft. Do you think this would help with the drifting and help with steering control as well. The boat is not a drop V hull. Any thoughts would be great.

    Thanks
    Devin
     
  2. PAR
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    PAR Yacht Designer/Builder

    Welcome to the forum. A skeg might help, but you're suffering from a couple of problems. First the boat is wandering around because the I/O drive isn't very efficient at low speeds. This wandering around , which is common on that type of drive at low speeds, is compounded with excessive windage forward. No skeg in the world will help this. Install the skeg, but except for low speed maneuvering, where it might help a little with straight line tracking, in contrary winds, you're pretty much screwed. The pilothouse is acting like a sail and you can't counter this without a 36" fin under the boat and even with this 36" fin, she'd still wander around in cross winds, just not quite as bad. Sorry for the bad news, but it's not uncommon with tall, light, small craft. Install the skeg, it'll help low speed tracking anyway. It's not two birds with the same stone, but it'll help get one of them.
     
  3. tunnels

    tunnels Previous Member

    Get a thruster maybe !!

    Hows about a bow thruster ?? this could solve a few problems !! If it possible to fit one that is They come in a big range of sizes for all types of boats !!worth a look at i reckon !:p
     
  4. PAR
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    PAR Yacht Designer/Builder

    There's not a lot of forefoot bury on a 1977 Crestliner, so unless it's a drop down style of bow thruster, not a very probable boat for a thru tube design, not to mention the cost of these things.
     
  5. tunnels

    tunnels Previous Member

    only a sugestion !! must be some way of making one fit . !!:D
     
  6. PAR
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    PAR Yacht Designer/Builder

    On boats like that a bow thruster would be a wee bit over the top. The only practical solution is a drop down type, but again over the top for a 22' shallow V hull. A boat with a lot of windage can benefit from twin engines, but this is a hell of a cost to bear too.
     
  7. supremei
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    supremei New Member

    Adding a small keel or type of skeg

    Hello everyone, thanks for the reply's, I think a bow thruster would be over the top for this boat. The large fin would not work. I trailer it and that would open up a can of worms. My main concern is better control around the dock. So if I add a skeg aft it help with the control at docking speed. Maybe one starboard and one port. Or should it be in the center.

    Thanks
    Devin
     

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  8. tom28571
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    tom28571 Senior Member

    Your question has already been answered and there is very little that you can do. All boats of this type have similar problems with side drift when docking in crosswind. It is a penalty we pay for the many important advantages of the type. The best solution is training in such conditions as well as effective rub rails on the boat and protective stuff that you can hit on the dock and pilings. Approaching with more speed when you learn how to handle it is one way to minimize side drift. Make sure you can tell just where the leg is pointing when you give it some reverse thrust to stop though. Some keel does help if you can tolerate the draft.
     
  9. supremei
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    supremei New Member

    Thanks everyone!
     
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    Looks like a boat that has a lot of height out of the water nowadays and not much depth under it. Don't think fitting skegs is going to be much of an idea, may even make it worse. Moral of the story is if you build a high superstructure on an existing design, expect changes in handling.
     
  11. ldigas
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    ldigas Senior Member

    What is a "drop down type bow thruster"? It is probably only a language issue, but I've never heard of the term.

    In the meantime, coming back to the original question, I wonder if something like this could be installed

    http://www.marinno.com/e/application.html

    although the hull does seem to be rather unsuitable for any kind of thruster in the fore area.
     

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

    Drop down thrusters fit inside a trap door, which drops down when needed, though is retracted flush with the hull when not in use. A pod, like the one you've shown could work, though is this style may rob a fair bit of available power through additional drag, on a full plane hull.
     
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