Very long and skinny pontoon hulls

Discussion in 'Boat Design' started by Saqa, Jun 9, 2021.

  1. Mr Efficiency
    Joined: Oct 2010
    Posts: 9,924
    Likes: 888, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Air props suit swamps, not Hervey Bay !
     
  2. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Well then throw in a couple of ideas on how to get the power down on a foiler! :p
     
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 9,924
    Likes: 888, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    See if you can find that story on 9 News about the Venice foil speed boat, it looked like the drive was down through a vertical strut aft, if something like that could be perfected, gliding along a couple of feet out of the water, it would beat the pants off conventional boats, less drag and no slamming, the catch may be if you hit something
     
  4. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Not that hard to do in Hervey Bay! Whales, dolphins, a million turtles, a billion stingrays, dugongs, trillion sandbars, logs, crab pots, kayaks, Bayans in tinnies slamming tinnies and more

    I like the idea of some kind of skimmer more
     
  5. Mr Efficiency
    Joined: Oct 2010
    Posts: 9,924
    Likes: 888, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    I think your concerns on that score are justified, if the foils hit something, it could get nasty. That would need to be assumed (that it will happen) in the design
     
  6. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    I have been looking up some engines. About $3000 roughly used to cheap new 1000cc for about 85-95kw and average 200kg
     
  7. gonzo
    Joined: Aug 2002
    Posts: 15,198
    Likes: 928, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Long skinny hulls start to submerge at high speeds. This phenomenon was discovered in the late 1800's and limited the top speed of boats until planing hulls were developed.
     
  8. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    I did not know this. Another issue is foils hitting things here. My neighbour is a jetski tour guide and they are always hitting things. His tinnie is all dented underneath too. My own current boat tends to shrug off most impacts like those though

    I have been reading up on the sea sleds and looking forward to seeing the results from the "madness". But I think to be effective it would mean a lot bigger and heavier solid boat that I couldn't live with. I am trying to also merge my RIB drawing to a cross between a WIG and a sled or tunnel cat type air cushioned boat
     
  9. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Windknife Aluminum Extrusions https://duckworks.com/windknife-aluminum-extrusions/

    Do you mean to use something like this as the strut? Maybe something big enough to send a prop shaft down to a right angle box? What do you think about shooting the exhaust down that hollow to quieten the motorcycle engine a bit?
     
  10. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Will the pontoons behave better with a for and aft trim tabs in high speed forward motion? Instead of a foiler, turn it into a skimmer. What do you guys recommend size wise for a one-person high speed minimalist tube based pontoon boat. Let's consider a single 1000cc motorcycle engine turning an air prop

    Any guidance towards a feasible option will be greatly appreciated
     
  11. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    I am able to execute fine build detail, so having some WOW factor is desirable. I am trying to settle on a base vessel that I can use to do all sorts of experiments like foiling and plane padding and wings and such. I think Rob hit the spot with the aesthetics of the "bucket list" concept

    Really partial to a main hull that looks like that (or cat config)
    About 8m
    One-seater
    Pair of stabilisers (if tri config)
    Happy for it to draft up to the tube at rest, like the idea of plane pads to bring the lot to the surface underway
    Maybe commercially made outboard foils as plane pads ( could be less prone to hitting things)
    Fairly protected cockpit
    Air prop (less hitting things, more experimental flexibility
    Exhaust through the hull maybe (for quietening)
    Like a stone skimmed across the surface...
     
  12. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    [​IMG]bl by Jonny TooBad, on Flickr

    Just drew up a 3m long 50cm wide ends for the bucket list look, will add more chines to give a more compound look. A pair of those joined together with a 2m length of tube about 45cm dia to end up with a 8m hull or two. Demountable at the tube. I work it out to be roughly 1600L volume for one complete hull joined to a 8m length

    One of this fitted to each blade as a plane pad

    SE Sport 300 Black Outboard Hydrofoil 200812Default Title https://www.freddys.com.au/products/se-sport-300-black-outboard-hydrofoil-200812?variant=30436941758557&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&utm_campaign=gs-2019-11-24&utm_source=google&utm_medium=smart_campaign&gclid=Cj0KCQjw8IaGBhCHARIsAGIRRYpbDmIbW8hw8_QohnGzgExHhtAVfw9Lx5h2P0ytoHBpeifJm5mXGUgaAvFEEALw_wcB

    What do you guys think? Any issues that I am not seeing?
     
  13. portacruise
    Joined: Jun 2009
    Posts: 1,196
    Likes: 66, Points: 48, Legacy Rep: 218
    Location: USA

    portacruise Senior Member

    Small hovercraft along the lines of "less hitting things"does not require long streamlined hulls and some of the associated issues.

    Another possible idea "like a stone skipped" is Hull air lubrication,

    Hull air lubrication: future and challenges | SSPA https://www.sspa.se/ship-design-and-hydrodynamics/hull-air-lubrication-future-and-challenges
     
  14. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Good article. Does a tunnel system like a planing cat approach the cavity system underway? I am very intrigued by a paper dart type RIB riding on pressurised air like a sled. In the other thread, I just posted pics of the RIB I am currently drawing. Its based a bit on the bottom of my Smartwave SW3500 and some hobby kites that I have made in the past. With the right COG and ballast, something like that might just be a good skimmer
     

  15. Saqa
    Joined: Oct 2013
    Posts: 649
    Likes: 15, Points: 18, Legacy Rep: 75
    Location: Hervey Bay

    Saqa Senior Member

    Are there any single pontoon boats speedy boats out there?
     
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.