Hull with the least wake

Discussion in 'Boat Design' started by silentneko, Jun 21, 2021.

  1. silentneko
    Joined: Jan 2014
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    silentneko Junior Member

    Traveling through a no wake zone got me thinking. What hull characteristics/shapes create the least amount of wake?
     
  2. BlueBell
    Joined: May 2017
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    BlueBell "Whatever..."

    The ones designed to at service speeds.
    Some ferries have gotten very low wakes at 19 - 20 knots.
     
  3. Ad Hoc
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    Ad Hoc Naval Architect

    Length - Displacement ratio.

    If you have a boat with an LD ratio of 5.0 it will create a lot of wash.
    If you have a boat with an LD ratio of 9.0 or more, it will create very little wash.

    Thus if your sole objective is to have a vessel with minimal wash... then you need a design with a high LD ratio.
     
  4. cthippo
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    cthippo Senior Member

    So asininely long, or a SWATH?
     
  5. Ad Hoc
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    Ad Hoc Naval Architect

    The type of hull form is not relevant.
    Just a high LD ratio....
     
  6. Saqa
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    Saqa Senior Member

    Just a random thought, I get this image of a hollow tubular hull with a scoop opening in my head. If all the water being pushed aside by the nose gets pushed through, does it still create as much of a wave?
     
  7. bajansailor
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    bajansailor Marine Surveyor

    If you have a hull like this, where do you get the necessary buoyancy from, if it is hollow with water flowing through it?
     
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  8. Saqa
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    Saqa Senior Member

    I saw something at my kids swim school. They were using PE foam sheet rolled into tubes. Each sheet about 4' x 8' could float 3 kids. So I suppose the wall thickness providing bouncy? Internally tapered lip is what I meant by the scooped mouth

    Think a pair of tubes with internal props in cat config with enough wall bouncy to float the same 3 kids, the deck structure and hardware
     
  9. bajansailor
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    bajansailor Marine Surveyor

    Your proposal above sounds fiendishly complicated - and I doubt that you will get much, if any, gain re resistance reduction.
    More likely the resistance would increase.....
     
  10. Saqa
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    Saqa Senior Member

    Please do not read any combative tone in this......

    Where would that degree of complication be?
    Which physical points would offer that increased resistance?
     
  11. bajansailor
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    bajansailor Marine Surveyor

    Complications -
    Building inner and outer hulls, and adding buoyancy between them.
    Weight of these two hulls, along with the materials cost, and extra frictional (and probably wavemaking, if your Prismatic is shot to hell) resistance, all when compared to a more 'classically conventional' hull form that has been optimised (to the max re so much existing research data out there) for the desired speed.

    Edit - maybe you just need a scaled down version of this beast?
    ZR48 Corvette Boat Powered By Mercury Racing Twin Turbo Marine Engines Delivering 2.700 Horsepower Gets Away From The Coast Guard! - https://infoditore.info/2021/06/13/zr48-corvette-boat-powered-by-mercury-racing-twin-turbo-marine-engines-delivering-2-700-horsepower-gets-away-from-the-coast-guard/
     
    Last edited: Jun 22, 2021
  12. cracked_ribs
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    cracked_ribs Senior Member

    Be gnarly wave interference inside that pipe, to say nothing of wetted surface area.
     
  13. Saqa
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    Saqa Senior Member

    Cant be that complicated:
    to make a tubular glass former with the skin required for one side of a foam/glass composite
    to run appropriate thickness PVC foam sheets through a table saw to rip strips
    to plank the former with the strips
    to apply glass for the outer skin
    to fit a prop internally with a shaft centrally suspended
    to run power to the prop shaft with 90 degree trans
    to implement half O receptacle for the tube that provides connecting points for the cross beams
    Cant be that hard to fit a foam glass "jon boat" on the beams for reserve bouncy and cockpit
     
  14. Saqa
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    Saqa Senior Member

    So the ducted prop with have gnarly wave interference inside, but I don't see how would that increase wake? Please elaborate?
     

  15. latestarter
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    latestarter Senior Member

    The boats following the competitors on an Olympic rowing course, where low wake is important, are IIRC usually catamarans.
     
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