SpeedDream: World's fastest sailboat?

Discussion in 'Boat Design' started by JosephT, Mar 9, 2012.

  1. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ====
    You're right: cost = pain(at least on my boat)!
     
  2. groper
    Joined: Jun 2011
    Posts: 2,483
    Likes: 144, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    This video proves nothing about whether a kite will perform better to windward compared to sails...

    Your comparing apples to oranges to plums...

    A kiteboarder has a power to weight ratio higher than any other sail craft on the water...

    To make an even remotely fair comparison, one would need to rig a kite (with equal projected area) and a conventional sail rig on a pair of identical hulls then run a race around the bouys...

    Kites reach and go downwind very well, beating hard to windward they cannot point like a good sail rig will...
     
  3. Timothy
    Joined: Oct 2004
    Posts: 307
    Likes: 16, Points: 18, Legacy Rep: 202
    Location: canada

    Timothy Senior Member

    "A kiteboarder has a power to weight ratio higher than any other sail craft on the water" Isn't that the point?
     
  4. ancient kayaker
    Joined: Aug 2006
    Posts: 3,497
    Likes: 147, Points: 0, Legacy Rep: 2291
    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Not really. That isn't even true of motor racing, where cornering and braking ability count at least equal. In my experience on the water in anything except a powerboat, I spend more time going upwind than downwind. In a sailboat I spend more time working my awy upwind than all other directions together. Other, better sailors in better boats do better, that's natural, but upwind ability still counts far more than equal to other sailboat abilities.
     
  5. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    -----------------------------
    The race was upwind and downwind. The kite won-that says something about the kites windward ability, I would think....
     
  6. Timothy
    Joined: Oct 2004
    Posts: 307
    Likes: 16, Points: 18, Legacy Rep: 202
    Location: canada

    Timothy Senior Member

    And that brings us back to Speed Dream. increased righting moment is what multi hulls, canting rigs, canting keels, foilers and movable ballast are after. Why? so they can carry more sail for more power with less weight and weted surface area. I am not a kite boarder . I don't even like them but I think the new gybing windsurfer like racing boards can make their way upwind as fast as a windsurfer even if they don't point as high and even that is debatable. I watch them do it every day.
     
  7. groper
    Joined: Jun 2011
    Posts: 2,483
    Likes: 144, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    Nope, it says more about the kiteboarder having way more power to weight ratio...

    Have you seen the other video? it shows the moth ahead of the kite at the end of the upwind leg... then on the downwind leg the kite blows past him...

    Dont get me wrong tho, a kite has some very special traits and i suspect we will see more kites on boats and yachts in times to come... The problems arise from practical and safe handling of them, especially launching and retrieving them. Hundereds of kiteboarders have sadly lost their lives using these types of sails, its quite a dangerous sport... But these problems aside, the power even a small kite can generate on a downwind reach must be experienced to be believed - you have the apparent wind of the speed your sailing, plus the windspeed, and with a kite you can generate additional airspeed over the sail by sweeping the kite thru the "window" in which it flies - i noticed the kite speed record the guy was not using this last form of building speed and tells me he could have gone faster- lift is proportional to velocity (airspeed) squared, so the power is impressive for such a small sail...

    heres a little taste of what im talking about...

     

  8. ancient kayaker
    Joined: Aug 2006
    Posts: 3,497
    Likes: 147, Points: 0, Legacy Rep: 2291
    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    - sounds like the faster-than-the-wind downwind tacking technique that fast boats can use . . .

    Many years ago I recall noticing the extra lift when towing a model glider. In competitions launchers would get a plane climbing at a rate many times faster than wind speed and snap it off the tow line to gain extra height, line length being limited by the rules.
     
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.