Whale Tails

Discussion in 'Boat Tips' started by Katmandeux, Aug 31, 2007.

  1. Katmandeux

    Katmandeux New Member

    Messages:
    1,618
    State:
    Checotah, Oklahoma
    There are a number of these things on the market, and they all make some pretty extravagent claims, but do they work?

    Specifically, on small, light skiffs, with just one fatboy aboard, will they compensate for all that weight in the stern, and make the hull plane/get the bow down at lower speeds?
     
  2. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    It works. Its robbed from the airplane wing.
    An airplane wing gets most of its lift from the air rushing over the top of the airfoil.
    The Doel Fin accomplishes the same thing with water.

    I put one on the last bassboat I owned. It was a 16 footer with a 60 horse on it.
    It made it an entirely different boat.
    My fuel mileage nearly doubled. I could stay on plane at lower speeds. Get on plane quicker.
    They are cheap now. Back then they had just come out and were pretty expensive.
     

  3. dougc

    dougc Active Member

    Messages:
    1,711
    State:
    Independen
    Yeah, like Mark said. I run one on my 16' v-hull Tracker w/40hp Evinrude on it, and it made all the difference in the world.
     
  4. whiskers77

    whiskers77 New Member

    Messages:
    318
    State:
    Southern California
    Great question! I had wondered the same thing myself. Glad to hear it does work if I consider buying one.
     
  5. Arkansascatman777

    Arkansascatman777 New Member

    Messages:
    7,782
    State:
    AR

    I agree with both of these posts. We put one on are 20 ft. wareagle with a 115 4 stroke and it made it a different boat. Well worth the $'s spent.
     
  6. catfishcentral

    catfishcentral New Member

    Messages:
    1,497
    State:
    OK
    I like mine. I got a 17ft aluminum with a 75 horse on back. I can see quicker holeshots, getting on plane quicker and plane on lower speeds. Now as far as the claims of quicker speed I may have gained a 1 mph or so. Better gas mileage in all going to depend on how you use that throttle. Since you can plane at lower speeds you will use less gas when you drive slower. If you still drive at the same speed you won't see any fuel mileage increases.
     
  7. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    You'll gain you fuel mileage in getting on plane quicker and being able to keep it on plane at a slower speed.

    My boat was terrible on a hole shot. You had to coax it up on plane and once on plane you couldnt go below 23 MPH.
    With the tail I was on plane very quickly and could stay on plane below 15 MPH. I would go through 12 gallons of gas before lunch with a 60 motor and fishing most of that time. With the tail I no longer needed to stop at all the marinas to top off halfway to where I was going because I was afraid my fuel wouldnt hold out.
    My fuel savings was barking in my face. Fishing these same lakes with the same gas needle and driving past the marinas I used to stop at out of need for fuel.
    I will agree every user of a doel fin woont have the same fuel mileage results I did. My boat was terrible. I could have thrown a danforth anchor off the stern and improved my fuel mileage.

    The tail creates lift. It lifts the back of the boat. The speed doesnt come from the tail itself it comes from the lift created by the tail.
    I saw an increase of 3 MPH with mine.

    I've seen a few racing sailboats in the 6 meter range that have had wings built onto the tiller.
    They do it for the same reason. It lifts the stern of that sailboat higher out of the water for less drag.
     
  8. 1sporticus

    1sporticus Active Member

    Messages:
    1,006
    State:
    Iowa
    Mark J has nailed it one the head. I've used them for years on all kinds of boats, and it's enhanced performance on every one of them. Later Andy
     
  9. Ed Lacy

    Ed Lacy New Member

    Messages:
    40
    State:
    Modesto, Ca
    I have a 20' "toon" and once in a while, the prop will cavitate. The engine revs up and the boat slow to nothing. When I back off on the throttle, the water gets around the lower unit again, and then everything is normal for a while. I have the engine tilted as far forward as possible and it still happens.
    It seems to make little or no difference how the boat is loaded, though maybe a little worse when there is an adult in the front of the boat.
    It's a '96 Johnson 50 SPL, 12 1/2 X 13 prop. I get about 15-16 mph@3600 and about 21@4900. So I think the prop is alright, wondering if a whale tail would help with the cavitation problem.
    Help.................
     
  10. Mickey

    Mickey New Member Supporting Member

    Messages:
    14,592
    State:
    Illinois
    I agree with all the postive post. I added one to a 120 hp Johnson and gained everything mentioned. I also noticed a difference in steering torque. A big improvement. Worth your money.:smile2:
     
  11. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill

    Edd it will make yours worse what you need to do is lower that motor on the transom one bolt hole. That will let thet lower unit down in the water a little deeper.
     
  12. killentime99

    killentime99 New Member

    Messages:
    98
    State:
    north carolina
    Thanks for the info Bubbakat. I have a 24ft pontoon with the same problem.
    Ill try lowering the motor.
     
  13. Ed Lacy

    Ed Lacy New Member

    Messages:
    40
    State:
    Modesto, Ca
    The motor is as low as it can go on the transom. The bottom of the wave diffuser, just ahead of the lower unit is about 2-3 inches above the cavitation plate. The motor has a 20" lower shaft and if I were to put a 25" on it, if I could find one, I don't know if that would be the cure or not.....
    Thanks much for the comeback though, it's really appreciated.
    Ed
     
  14. Katmandeux

    Katmandeux New Member

    Messages:
    1,618
    State:
    Checotah, Oklahoma
    Ed, if you haven't already, try a cupped prop.
     
  15. ka_c4_boom

    ka_c4_boom New Member

    Messages:
    2,252
    State:
    Bedford,Ky
    i have a 16' flat bottom river jon with a 40 horse i run two different props , the one is 11.4 x 12* i use when the river is full of logs and debri the other is 10.4 x 15* i run when the water is cleaner , both props get me on plane fairly quik would a whale tail increase my milleage ?
     
  16. jtrew

    jtrew New Member

    Messages:
    4,404
    State:
    Little Rock, AR
    I've got a Lowe 1648 Bigjon with a 25hp 4 stroke on it, and a whale tail definitely helps get it up on plane and keep it there.
     
  17. mr.catman

    mr.catman New Member

    Messages:
    10
    State:
    ohio
    would it work on a 14 1/2 ft v hull with a 15hp tiller and two large size fishermen?
     
  18. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    Y'all do a little research on the web, or whatever, before you jump, now. The whale tails can be a huge help on some rigs, so-so on others, maybe little if any on a few, too. Just be sure what you're doing, in case the miracles don't occur. :wink:
     
  19. dougc

    dougc Active Member

    Messages:
    1,711
    State:
    Independen
    Your boat is a perfect candidate. Underpowered boats generally will show better results.
     
  20. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Its going to help with planing but there is no cure for an underpowered boat except putting more power on it.
    It will still be a dog with 2-3 people onboard, you'll plane better and your fuel mileage will increase. Be resigned to the fact its a one man fishing boat. I owned one too.:big_smile: