Tantra 2014-a Performance Daysailer

Discussion in 'Sailboats' started by Doug Lord, Sep 10, 2014.

  1. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    I did a thread some time ago about this boat which was and still is one of my most favorite designs. She sailed with an 80 sq.ft. rig back in 1978 or so. My last iteration of the design was to use curved "C" foils in trunks inside the "leeboards" to allow foil assist-not full flying which back then would have required wands and a special type of "C" foil.
    But in 2011-13 the world of hydrofoils changed dramatically with the TNZ invented UptiP foils. It didn't occur to me until a few days ago that uptip foils are the answer to making this boat a viable, easy to sail foiler for one or two people. The boat can easily be beach sailed with the retractable foils.
    The shape of the boat lends itself to light weight building and would easily handle the extra weight of a cooler and dry stowage.
    So here are some updated sketches and old photos of the first prototype.

    Pictures, L to R, 1) "Tantra art" by my brother Frank, 2) Tantra proto sailing with US 1 rig, 3) Tantra with experimental square top rig, 4) Tantra hull with molded in leeboards that allows the boat to point with the US1 fleet, 5) Tantra circular cockpit with dry stowage, cooler and reverse curved vangeller, 6) Frank helping to get the boat ready for her first test sail with the US1 rig, 7) Tantra 2014 Sail Plan, 8) Tantra 2014 with everything the original had plus retractable seats, 9) Tantra 2014 curved, retractable, UptiP foil:

    Attached Files:

    Last edited: Sep 11, 2014
  2. rcnesneg
    Joined: Sep 2013
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    Location: Utah

    rcnesneg Senior Member

    Pretty cool idea! How much do those little "float extrusions" actually provide extra stability? I imagine without a foil it would be nearly zero. I doubt it could fly the main hull as in the drawing in the beginning. Seems like maybe 20-30 pounds of buoyancy max.
  3. Doug Lord
    Joined: May 2009
    Posts: 16,678
    Likes: 341, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready


    Thanks! No buoyancy to speak of in the molded in leeboards- my brothers drawing was just a cartoon*. With the uptip foils she'd definitely fly -and in pretty light air too. And the cool thing with the foils is that they're fully retractable so the boat can sail off a beach. The fore and aft parts of the molded in leeboards extends below the retracted foil so the foil would never touch the bottom.
    Probably would use a less radical rig though it has been tested on a model and showed a lot of promise in light and medium air. For heavy air the ribbon jib would be rolled around the very short jib boom.
    The idea is a fun, fast boat that can take supplies for a long daysail or an overnight on an island. The molded in leeboards mean she can sail upwind in very shallow water....

    *The asymmetrical, toed in molded in leeboard on the original boat did develop vertical lift when heeled and fast but never came close to flying the hull.
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