Handling Characteristics of the 18 and 20

Discussion in 'Drivers Corner' started by jim, Jan 12, 2008.

  1. jim

    jim Hydrodyne 18 Specialist

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    It has been a long time since I drove a 20 and I did not drive it much.

    How about some of you that have driven both describing the differences in handling?

    jim
     
  2. Dyna-Kid

    Dyna-Kid Boat of the Month

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    Club de Skinautique
    Jim,

    I've driven both and like you, not that much and it was a long time ago. Is the hull on the 20 that much different than that of an 18? Is the enhanced "lip" that was added on the 20 and 17.6 be the only addition to the beam (width)?

    Would the lower part of the hull (the part below the lip) be the same?

    (see rear hull shot of a 17.6 below)

    Thanks,

    Kevin
     

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  3. markbano

    markbano Hydrodyne 18 Specialist

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    Jim knows this stuff better than me but I think the answer is "no" - the 17.6's and 20's are wider and deeper hulls. The essential, proportional shape of the bottom of the hull (flat bottom) has remained similar to the 18's. However, the proportion of true rounded chine to the entire, higher side seems to be less on the newer hulls. The 18's have a true rounded chine that extends about 50% up the hull's total height. That, with shallow draft, is part of what makes them fun to drive (A narrow boat with a rounded chine, they will roll right up on their side). I'm not sure how the edge, or lip, washes out going forward on the sides of the 20's and 17.6s relates to the 18's but the 18's carry that lip all the way forward, with a rise to the bow.

    I've never driven a 20 or 17.6 but my guess is, with the deeper, wider hull, and the sharper, lower cut-out from the rounded chine would make these boats more resistant to the rolling moment in a turn (i.e., they would turn flatter).

    Markbano
     
  4. dynebob1

    dynebob1 Boat of the Month

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    Mark,

    I have owned two twenty footers, and they do turn flatter due to the additional width and the way the bottom flattens out at the sides. They seem to roll up so far, and then hang there.
    In my opinion, the 18's are more fun to drive. Sort of like a sports car.

    Bob
     
  5. Dyna-Kid

    Dyna-Kid Boat of the Month

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    Lake Metigoshe, ND
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    74 18 Hydrodyne 150 / 06 17.6 Dyna-Ski 150 Merc FS
    Ski Team:
    Club de Skinautique
    Hey Guys,

    I know the 18'er rolls up onto its side and on the twin rigs the outside prop and exhaust come out of the water (always sounded awesome and made for a cool boat demo) but would the 20'er roll up as much?

    The last I heard was that many clubs stopped doing "boat demos" cause some people have actually rolled a dyne? Has anyone actually rolled one themselves or heard of one being rolled?

    (pic of a 18 twin rig from another thread attached)

    Kevin
     

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  6. jim

    jim Hydrodyne 18 Specialist

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    The 17.6 and the 20 are a foot wider than the 18 which is a bunch. The chines and the proportions look very similar to me.

    I have driven a 17.6 and the extra beam allows it to perform well with the fuel tank in the rear, leaving a bunch of storage under the fore deck. It turns flatter than an 18. There is more difference in the wake than I would think.

    jim
     

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