Tropical flooding rivers... please help me.

Discussion in 'Propulsion' started by Darien, Aug 14, 2015.

  1. SamSam
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    SamSam Senior Member

    I'm thinking you don't want to go 40-45 mph in that 11 ft boat.
     
  2. Darien
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    Darien Junior Member

    google "mini jet boat" for some entertainment. Again... should I consider a jet? Does the suction make them safer at the 70+mph that skis can do? I already said I want to go 40+mph, now I need design help because I don´t know squat.
     
  3. rasorinc
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    rasorinc Senior Member

    Are you serious? You want to go 40++miles per hour in a thin skin boat in muddy waters that you know has lots of debris
    some of which is real heavy??? Get a steel hull air boat......................................
     
  4. Darien
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    Darien Junior Member

    Yes. I´m serious. The lower reaches of the river are wide and deep without major obstacles. The upper reaches would be slower travel with the logs and gravel bars.
     
  5. markstrimaran
    Joined: Dec 2014
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    markstrimaran Senior Member

    Search " diy surface drives" on this site. Lots of info.
     
  6. whitepointer23

    whitepointer23 Previous Member

    Maybe tom kanes drive setup could work for you. The problem you have is . No experience at all from the way your thread reads. The chances of you making something reliable are pretty small and could leave you stranded on a remote river or worse.
     
  7. Darien
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    Darien Junior Member

    thanks Mark. I have seen a lot of those threads and will continue to peruse.

    Whitepointer can you please link to Tom Kane´s drive? A search on the site of those words turns up nothing. Correct, I have not built a boat. But I have built lots of mechanical stuff and have an engineering degree for what that´s worth. My work partner is a professional mechanic from Panama and quite the Macguyver. I´m hoping that constructive comments on this site will help me do better than I would otherwise so I can serve the indigenous people of Panama more effectively.
     
  8. whitepointer23

    whitepointer23 Previous Member

    Search tom kane or lifting pivotal drive on this site or google. Tom will reply to this thread when he sees it anyway.
     
  9. Darien
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    Darien Junior Member

    ok. my apologies. I had seen all these threads but didn´t understand that they were arranged in pages, so I´d only read the first page of each one. I´ll do some more homework.

    I still haven´t come across anything for a tiny diy surface drive. Thanks for all the help thus far.
     
  10. Darien
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    Darien Junior Member

    ok. I picked through the most relevant thread "diy surface piercing" much of which was about the actual topic :)
    While all the pivotal business with thrust bearings seems fun, I must admit that simplicity and reliability would prescribe either a jet or a direct drive short or long tail in the short term.

    I had not remembered seeing a thai boat like on pg 9 of that thread with the transom mostly cut out, allowing the engine to sit low. That solves my concern with the high CG of the go-devil or mud buddy. Would it be worth trying to optimize the angle of the propeller on such a long tail set-up like they do with the go-devil or mud buddy via the the geared linkage? Can anyone recommend off the shelf parts to accomplish this (ie have you done it)? Would it be silly to fit a big boot, kind of like in the shape of a boot on a car´s stick shift, to make it a little more protected from water infiltration with the cut out transom?
     
  11. Deering
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    Deering Senior Member

    Why not get an outboard with a jet lower unit?
     
  12. Darien
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    Darien Junior Member

    heavy... top heavy... Anything not fixed to the boat needs to be totable to the huts on a shoulder.
     
  13. Richard Woods
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    Richard Woods Woods Designs

    I assume you are talking about the Kuna Yala? For what it is worth, I've cruised that area for several years and been up rivers by dinghy to collect fresh water in the gravel beds.

    I don't think you want to go too quick! IIRC there is generally a bar at the entrance and then it gets deep again, but full of fallen trees, until you get to the gravel beds - when you cannot/should not motor to prevent polluting your drinking water. So you need a boat that can be rowed/paddled

    Rolf Eliasson has also cruised that area and may be worth contacting

    Mind you I haven't been too far towards the Columbia border, cruisers weren't too welcome there

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  14. Darien
    Joined: Aug 2015
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    Darien Junior Member

    Thanks for the reply. We don´t work in Kuna Yala right now. Yes, those are small rivers with no communities (not that I´ve been on any of them). We work mostly on the Chucunaque and its branches (the big system that empties into the Pacific).
     

  15. Darien
    Joined: Aug 2015
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    Darien Junior Member

    longtail

    I found a website of a guy who builds longtails.

    It has some good info on balancing the engine, lowering CG, etc. He claims a 2" draft. But one comment puzzled me.
    "The best engine I have found is a 13 hp. Honda GX 360. I tried a much bigger engine but the weight cancelled out the additional power and the performance was similar to the 13hp engine."
    Why would that be true for his setup?
    fyi... I have contacted the website but have not yet received a reply.
     
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