"pocket" transoms

Discussion in 'Powerboats' started by RTN, Apr 10, 2005.

  1. RTN
    Joined: Apr 2005
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Lutz, FL

    RTN New Member

    In referance to "pocket" transoms like those found on flats and bass boats.....what is their purpose.
     
  2. DaveB
    Joined: Dec 2003
    Posts: 129
    Likes: 1, Points: 0, Legacy Rep: 11
    Location: Canada

    DaveB Senior Member

    I think that they increase buoyancy aft (allowing for larger engines) and increase the running length facillitating planing (providing more lift aft, preventing squatting)... Could be wrong though... just my 2c

    Dave
     
  3. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    Sounds right to me. The closer the engine moves to the center of a boat, the larger the engine weight range it can safely handle.
     
  4. mackid068
    Joined: Feb 2005
    Posts: 857
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: CT, USA

    mackid068 Semi-Newbie Posts Often

    Pocket transom? As in a small transom?
     
  5. RTN
    Joined: Apr 2005
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Lutz, FL

    RTN New Member

    I must be using the wrong terminology. What I am refering to is the "pocket" section on the bottom rear of the hull.
     
  6. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    Everybody, I am referring to a POCKET TRANSOM as used in a inflatable boat. The 2 side tanks extend way past the engine to stabilize the boat in all weather conditions.What are you talking about?
     
  7. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    OK, I think you are refering to TUNNEL DRIVE as used on VERY SHALLOW running boats. They go easily in 6" of water at wide open throttle.
     
  8. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    They are without a doubt THE BEST boat on tidal flats. Do you need some web stes to check out?
     
  9. RTN
    Joined: Apr 2005
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Lutz, FL

    RTN New Member

    Cyclops has it figured out. It's not actually a tunnel hull. Is the purpose of the pocket hull to allow for a higher mounting of the outboard?
     
  10. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    Actually it is to run the props in a very WET mode of surface drive. Boat stopped, the prop is submerged. Race it up and the boat lifts on to a plane. Speed increases and the prop maintains suction and thrust. Carefull adjusting of motor height is required as boat load changes. Still, it will not suck all the bottom up like a true jet pump drive will and destroy it self. 1 Aluminum and spare prop is very reliable, out and back if you get careless.
     
  11. PowerTech
    Joined: Feb 2005
    Posts: 183
    Likes: 0, Points: 0, Legacy Rep: 4
    Location: FL,Keys

    PowerTech Senior Member

    pockets are the funk on fast flats boats.in lets more water get to the prop with the motoer higher like the other dude said.the pocket is a bite taken out of the transome doun were the drain plug is.A hydrolic jack plate and a pocket is the way to go for great speed and shalow water running.My old budy jon put a pocket and a pad on his hydrostream to get rid of the hook and that thing hauled ***.I got a old hews bonefisher with no pocket but I think the new ones have them.
     
  12. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    Web search. flats boats Plenty of companies with all the features. Enjoy
     
  13. RTN
    Joined: Apr 2005
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Lutz, FL

    RTN New Member

    As I understand it then the pocket actually directs water upward to allow the motor to be raised and still run without cavitating. How high can you raise the motor before loss of performance?
     
  14. PowerTech
    Joined: Feb 2005
    Posts: 183
    Likes: 0, Points: 0, Legacy Rep: 4
    Location: FL,Keys

    PowerTech Senior Member

    I don't know how high you can go up .some one may want the model of your boat and motor tipe to tell you something about that or a measure of the pocket or something.Or maby there is a general rule of thumb But I don't know.What I do know is hydrolic jack plates kick *** and you can adjust them on the fly for the optimum hight for plaining or high speed and with the trim adjust on the engine and a jack plate you can tune that baby rite in to the sweat spot when ever you want.
     

  15. cyclops
    Joined: Feb 2005
    Posts: 1,059
    Likes: 5, Points: 0, Legacy Rep: 38
    Location: usa

    cyclops Senior Member

    You are getting the idea of it. Take a 6" deep puddle of water. Start a powerfull wet/dry floor vacume cleaner. Move the hose end to the water surface. Nothing happens till you touch OR submerge the hose end. Then you can raise the hose end ABOVE the water surface. Touchy but DOABLE. In a OB boat you can eliminate MOST of the lower unit body drag. More efficient and faster. More prop protection with simple hull design. It works.
     
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.