Australian surf boat conversion

Discussion in 'Multihulls' started by surf boat man, Sep 24, 2008.

  1. GOTTABSOMEWHERE
    Joined: Jul 2008
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    Location: ST LOUIS MO

    GOTTABSOMEWHERE Junior Member

    Hey surf boat man



    Just saw a old pic of your (?) lanteen rig in a HOBIE conversion ?

    Actually you commented on a "DHOW" type sail.................I DID THAT !

    I WILL TRY TO SEND PICS E-MAIL.

    I used a "DORY" hull (much like your surf boat" Hung Dhow style lanreen rig from a "A" mast. Noom is 22' but mast is only 8' tall.........cool ?

    comments
     

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  2. basildog
    Joined: Dec 2008
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    Location: Gold Coast Australia

    basildog basildog

    Surf boat man
    I to saw that 'trimaran' Brunswick heads way,you were talking about. Dont know if it was the same boat , but the one I saw had floats and rig from Hobie 18
     
  3. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

    hi Surf boat man

    I did a similar conversion. I had an 18ft dory and I added a single 14ft outrigger.

    Photos can be seen here

    http://www.geocities.com/peterevans_33/new_outrigger_canoe_photos.html

    By the way where are you. The reason I ask is that a while back I built a different 14ft ply outrigger. It was built in Nowra NSW, but is now in Canberra on Braidwood (mother's place or sisters place). If you are in Sydney then you could score yourself a free outrigger, if you are prepared to drive a couple hours. I need to confirm that the outrigger still exists and has not been cut up and thrown away.

    I am a fan on just one outrigger. Though I must admit I had not tried a trimaran version.

    I am happy to share my experiences in converting my dory to a mulithull

    regards
    N Peter Evans

    peterevans_33 at yahoo dot com dot au
     
  4. GOTTABSOMEWHERE
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    GOTTABSOMEWHERE Junior Member

    Tridoryan



    HEY PETER AUSTRALIA
    Read with interest your post on outrigger/dory............
    really like your Dory.............looks very substantial.
    I went for a lightweight as it will not be out on the big blue ocean.
    Have not been on the water yet but will be in a week or so............
    Would like your comments on the "DHOW" type sail i homemade, see pic.
    No sailmaker wanted to get involved with this rig soooooooooo I did it myself.
    I think two floats will give it superior stability, don't ypu ?
    I'm real good at leaning over to pull up traps etc. and flipping over.......
    Now I can dance on either side or properly "moon" also.
    Have oarlocks placed on floats so I can sit on fdw. beam and row with
    a pair of 10 feet long (homemade also) oars. Also use these for rudders.
    Just for grims i have a "YOULOH" (?) FITTED INTO NOTCH ON STERN...PIC.
    Please check out my pic. and let me hear your comments.
     
  5. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

    Hi

    From your photos it looks as though you have a dory and a separate craft a hobie catamaran with a home made rig. In the future you are looking at joining the 2 craft to make a trimaran. Is this a correct summation of your situation?

    Some little things. A dhow sail is called a lateen sail. It should work well. Lateen sails are efficient, some downsides are that a lateen sail is a bit harder to reef than a normal sail. This should not be too bad as your sail seems of modest size and has a low center of effort. Another issue that can occur with Lateen sails is that when going downwind the spar can get caught in the water and trip up the boat, do not think this will be too much of an issue for you.

    One issue that I think will be a bit difficult will be tacking. A fellow called Kris Keluga put a Lateen sail on a catamaran and had issues with tacking easily. i have photos about somewhere. He used a bipod rig.

    Some other things, how do your plan on building your crossbeams, will you extend your present hobie crossbeams. Do you have access to a welder and tubing. I have seen photos of an aluminium grumman canoe conversion to a trimaran, they used an aluminium ladder as the crossbeams. In this case the outriggers were smaller than yours and hence loads were less

    I have only a single outrigger. One one tack it is a float and on the other it is a counter weight. This craft is called a tacking outrigger. They were once common, stretching from the Indian Ocean in Madagascar, to Indonesia, to the Pacific in New Caledonia and Samoa and more. My feeling is that one outrigger is stronger and safer than 2, but not as fast. (generalization here). If you google tacking outrigger, you may find some of these craft.

    My 2 cents worth is have a go with your craft, be smart and wear a life jacket and or wetsuit. See how it goes, if worse comes to worse you might try a different sail rig, be that a sprit rig on a lugsail like mine. As for rowing over the outriggers, may work. Feel that a Yuloh from the stern may be easier. If you have the budget, a small electric outboard may be used as a contingency.

    Does your craft go behind a car on a trailer? If so you may wish to consider the single outrigger setup with the outrigger (one hobie hull) carried up high and supported by some wood. This way you will have no assembly time, the slope of your dory hulls will assist in carrying your assembly at an angle.

    Are you more interested in speed, or more in going on long exploration trips (circumnavigation of some of those great lakes sounds cool)?

    good luck
    N Peter Evans
     
  6. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

    hi

    I am a bit daft. I looked again at your photo, but this time I zoomed in. You have already done your conversion. Do you have any comments on how well it sails? I have not seen anything like it before. That is a nice dory though, would be a shame to lose it by too extreme conversion. I would think the dory would be a pretty sale-able boat (easy to sell), should you be tempted to try and build a purpose designed hull to be a multihull. I guess it all comes down to what you want to do in the future.. and your budget

    N Peter Evans
     
  7. peterAustralia
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    peterAustralia Senior Member

    Before I go

    I see you do not have a board, you are relying on your hobie hulls for lateral resistance.

    In a trimaran, a rule of thumb is that the bottom of each outrigger should just touch the water when loaded. As such, your dory looks high up, and may not support as much weight as is the ideal. Another little thing, with new rigs, it is often hard to get the center of effort correct. If you are able to adjust your bipod/A-frame conversion fore and aft, to fine tune the setup, that may be useful
     
  8. bad dog
    Joined: Apr 2009
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    Location: Broken Bay, Australia

    bad dog bad dog

    Hobie floats (amas)

    I saw a sufboat cum trimaran at Port Douglas last winter - it used 16' Hobie hulls as floats. It seemed to sail reasonably well - in a very laid back non-competitive way - but then the winds were very light. The water was in fact like glass part of the day - great snorkelling, poor sailing.

    It inspired me to have a go at building a DIY tri with a maximum budget of AU$1,000, thus needing all parts to be found, scrounged, or second hand. I thought either of a surfboat, or an old 18' skiff as the main hull, with added freeboard.

    This project is still on my bucket list, so I'm reading this thread with interest.
     
  9. Fanie
    Joined: Oct 2007
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    Location: Colonial "Sick Africa"

    Fanie Fanie

    Hi surf boat man,

    I like the sail idea you have, it makes nice lift. I made an aft mast setup for a test trimaran that worked pretty well, I would consider adding a boom on the foot of the sail though, it makes better control and you don't have to tack when running.

    Personally I would have added two ama's instead of one.

    The hull looks like it is going to work very well.
     
  10. GOTTABSOMEWHERE
    Joined: Jul 2008
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    GOTTABSOMEWHERE Junior Member

    Hobie/dory Conversion



    PETER AUSTRILIA,
    Good to hear your comments...........Since I started this project, I've heard nothing but negative trash from the U.S. I have become immune !

    Yes it is two separate craft..........stock HOBIE hulls with beams were lashed to the Dory. I fashioned a "nest" or "saddle" for the aluminum beams and lashed them onto the HOBIE. Hulls have drop down boards. Width is as is and able to be trailerd on U.S. highways (no dismantling or set-up)
    I do understand beam could be wider but if it worked for HOBIE it will
    work as a tri. (I think ?)

    So far I've $300 U.S. invested......Will change out to a lighter sail material if this beast gives respectable performance.

    No I did not lose any sleep contemplating the center of the sail or placement of "A" mast. I simply strengthened the sections of the beams where they
    sat on the "nest" and lashed them there. Same with aft beam. "A" mast is metal lightweight metal fixed to beams at pooint of where beams rest on "nest" Mast is stayed at stock locations of original "HOBIE' MAST. A SINGLE BLOCK PULLY IS AT APEX OF "A" . Halyard from seat lifts spar to apex and tied off. Nose of spar (between hulls) swings as to allow spar to tack.Main sheet is stock HOBIE location. So at this point I have no idea how it will sail, really I'm only interested in getting form point A to point B in saftey, comfort and with all the stuff I want with me.

    I whole concept was to have a stable sail craft..............sit in a regular human type position (not crosslegged for hours)............ carry enought beer
    and food..........ability to detach DORY and row up a shallow creek.

    Am in the process of making a removeable narrow seat between fore and aft beams to row/motor/sail just the cat. Will also install a light weight small
    hoist, crank operated, to lift crab traps between forward hulls.
    Crabbing on the bay is a excellent way to pass the time and get supper
    without tipping over the side of convential boat. I'm interested in finding out how much of a load I can lift off the bottom this way.

    Also am thinking about a lightweight ladder/ramp.... to hinge on forward beam
    and drop down for beach ramp/diving/standing/ mooning platform.

    The more I think on it the more things come to mind

    Keep the jucies flowing
    GOTTABSOMEWHERE
     
  11. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

    Hi

    Dont listen to the negative people. There are always lots and lots of people willing to criticise. Additionally there a lot of people that think because you have not spent many multiples of ten thousand dollars, thus your craft is not adequate.. this again is bull dust.

    If your boat works well, then that is all that counts. If you use it, you like it and it works well, then the boat is a winner.

    The ability to detach the dory is cool. It looks like a Gloucester Gull by Bolger, did you buy or build it? It looks like a real cool rowboat.

    I guess in longer term you may wish to have greater beam(width). To achieve this you may need some sliding crossbeam/folding crossbeam mechanism. The downside is that this is more work and money. The upside may be more speed. So I guess the immediate next step is to go sailing and see how it goes.

    An aside, I have 2 weeks off work soon. Intend to spend 5 days or so circumnavigating Port Phillip Bay in my tacking outrigger. When I get back will share some photos.

    regards
    N Peter Evans
     
  12. GOTTABSOMEWHERE
    Joined: Jul 2008
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    GOTTABSOMEWHERE Junior Member

    Two Weeks Off !



    SURFBOAT MAN

    Yup...............would like to see pics of your trip.

    Yup...........I built the "DORY" it was a easy and lightly built.....3 sheets 1/4"
    plywood with epoxy over.

    Plans and building information is on net "cruisernews.net/dory/"
    Also "GOOGLE LOBO DE MAR ll" and "SOUTH HAVEN DORY PLANS"

    Let me hear from you after you return.

    GOTTABSOMEWHERE
     
  13. bad dog
    Joined: Apr 2009
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    Location: Broken Bay, Australia

    bad dog bad dog

    How ya getting on surf boat man? Have you made any progress? I have been looking at cheap 18' cats for donour hulls - they seem to be easier to come by than the main surf boat hull (I have been looking for one too, or perhaps an 18' skiff hull - that would make it a very different boat).

    Bad Dog
     
  14. CT 249
    Joined: Dec 2004
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    Location: Sydney Australia

    CT 249 Senior Member

    There was a converted surfboard tri on Lake Macquarie, Sydney, years ago. I can't really recall how it went, but with a conventional rig I think it was roughly as fast as a Trailertri; however it was sailed very well. The surfboat is fairly heavy so these boats won't be absolute screamers, but they can certainly be great fun.

    Dunno if lateen rig is the way. As soon as you have to buy a new sail you will end up spending $$$$$. Finding a second-hand rig from a competitive one design class is normally the best way, as they have plenty of "old" sails that have only done a few races going cheaply. For example, a pair of 16 Foot Skiff rigs could work. A couple of years ago my brother picked up a good foam sandwich 16 for about $1000 as a donor for a project boat. It provided two or three masts, loads of Harken ball-bearing blocks, a bunch of CBs, stays, and about 7 good sails. That's good buying, and the 16 hull would make a good fishing boat if you reinforced the transom.
     

  15. bad dog
    Joined: Apr 2009
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    bad dog bad dog

    Yep, years ago I had an old ply 18' that I used as a tender - it was stable, easy to row, and with a solid transom demonstrated that the length and beam are fine for local cruising for two. Using a foamy would lighten things up but local reinforcing of a few points may be needed, especially the keel if beaching when exploring inlets etc. Maybe even adding a timber keel - say tapered in profile from 30mm at bottom to 80mm abutting the hull - to distribute point loads over an area of foam to prevent crushing.
     
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