Angle on sides of jon boat

Discussion in 'Boat Design' started by msaxton, Apr 1, 2016.

  1. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    If you have a few boats under your belt, you'll do fine. Just pick an angle, that's roughly what you're seeing on other jon boats and you're not going to be far enough off, to matter all that much.

    With jon boats and to a lesser extent the garvey (which I think is a better choice for your needs BTW), the bottom rocker is much more important.

    The flat bottom hull form is the most efficient in terms of the power necessary to get on plane. They get up faster and can hang on longer at lower speeds, before falling off. They're also simple to build. On the flip side of the coin, they can pound unmercifully in a chop and will reach longitudinal instability (porposing) much sooner than other hull form types. The garvey hull is a fair bit better at staving off pounding in a chop, though these to can pound if driven too hard.

    [​IMG]
    Hard to see well, but note the rocker and entry angles.

    [​IMG]

    This is a shot of a well designed jon, up on plane a scooting along good. On a lot of jons, they just make a crease in the bottom and this becomes the bow transom. That approuch will pound worse. The photo shows it's a sweetly curved transition from the transom to the bottom and if done well, she'll trim with the bottom square with the water's surface. This lets the boat run level and drier.

    A garvey hull is basically a jon, but a shallow V bottom is worked in, making it handle rougher water more comfortably. It still has the squared off deck line on the bow, so plenty of deck space.
     
  2. Village_Idiot
    Joined: Oct 2007
    Posts: 382
    Likes: 18, Points: 18, Legacy Rep: 138
    Location: USA

    Village_Idiot Senior Member

    I have been on a few boats that had variable angles. They had more angle toward the bow, and less angle at the transom. And yes, there was slightly more beam about one-third aft of the bow than there was at the stern/transom.

    As for tripping...I run a 2460 pocket tunnel hull with electric/hydraulic jackplate. At full jackplate height, there is less than half of the prop below the boat hull. The boat is easy to throw into a drift in a turn, with no hint of tripping, and you'd need to nearly come off plane to recover from the drift, or trim the motor down. With the plate down, it is harder to throw into a drift, bit still little sign of tripping, but can recover much faster. Mostly, I just compensate for the drift, much like drift track racers do, and make wide turns, starting well in advance. It is very unnerving for my guests, and a boatload of fun for me. :) it is a very predictable drifter.

    I've also run a PolarKraft 1860 flat-bottom jon boat with ice runners on the bottom of the hull. Depending on motor height, I believe you could turn that thing at full lock at speed (33-34mph) with absolutely NO drifting. It would throw you out of the boat before it would drift. It would turn HARD and turn NOW!
     

  3. msaxton
    Joined: Jan 2014
    Posts: 57
    Likes: 3, Points: 0, Legacy Rep: 30
    Location: Duluth Minnesota

    msaxton Junior Member

    I am finally back from my sort of vacation,,,more driving than leisure transporting my parents motorhome back to Minnesota from Florida via Texas,,,I know, I took the long route. Anyway, I have definitely decided to build one of the folding jons in the video I posted earlier (post30 i think) I have purchased most of the materials minus the fiberglass and epoxy and should be getting started on it this weekend. Thanks everyone for any advice and opinions given.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.