How do you gauge your speed

Discussion in 'Laser Talk' started by Skygod1, Jun 8, 2007.

  1. Merrily

    Merrily Administrator Staff Member

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    Also, what do you think, people? Should we ask Bradley to split this thread? It's gotten away from gauging your speed.
     
  2. gouvernail

    gouvernail Active Member

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    how would we guage his speed and timing of the split?
     
  3. Merrily

    Merrily Administrator Staff Member

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    From the link that I suggested earlier, an RYA dinghy instructor (British certified instructor) says that you can either head up OR bear away when the apparent wind shifts forward, and the boat will accelerate. There are also some hints for gauging your speed. See below:


    "On a windy day, the Laser will plane if you point a little below a close-hauled course and hike like mad. in reality you go from displacement, to bow out of the water to planing; with noticable performance improvements at each stage. Watching videos of Lasers training you can clearly see three stages in the displacement to planing transition.

    My suggested explanation is:

    1) Boat accelerates and overtakes its bow wave ("official" planing definition) - bow lifts out of water.
    2) As boat accelerates apparent wind shifts forward (heads) so sails depower.
    3) Sailor trims in/bears away and suddenly accelerates.

    Things to look for at the transition are:

    1) The bow wave out each side leaves the sides of the boat much further back.
    2) Wind shifts forwards.
    3) Boat accelerates.
    4) If you are hiking you can probably see the bow lift if you are sitting forward.
    5) Transom wake turbulence decreases.
    6) You are moving faster than another Laser.
    7) The rest is instinct...

    In reality, what you should be focusing on is not "Am I planing, if so, how fast am I going?..." but more like:

    "How do I get this boat to go even faster?"

    In terms of performance, knowing if you are planing or not does not really improve your race results.

    One thing to note is that if your laser is going more than 5kts, then it has to be planing! You can plane and still not go that fast. The trick is to make the transition from slow planing to damn fast planing because anyone can get the flat aft section of the Laser to plane..."
    __________________
    Will Richards
    RYA Dinghy/Race Instructor
    www.saildisc.co.uk
     
  4. Merrily

    Merrily Administrator Staff Member

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    You are such a trouble maker! :eek: :rolleyes:

    What do you say to do when the apparent wind shifts forward, Gouv?
     
  5. tannerz

    tannerz New Member

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    look at the diagram again.. I added to it. I added a boat, and the dead zones in a few different places.

    In the middle of the diagram is a boat on the red wind line at 45 degrees to the wind, and a boat on the blue wind line at 45 degrees to the wind. they are pointing very different directions.

    On the right side of the diagram the boats are pointing in the same direction, as the wind comes forward (boat on the blue line), if no changes are made, it comes into the dead zone.


    If the wind shifts up (coming more from the bow), and you head up (more into the wind) you are now head to wind.
     
  6. Merrily

    Merrily Administrator Staff Member

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    Y'all are very kind to stick with explaining this. I've had an epiphany and I get it now. Bear away. The apparent wind has shifted and you just shift your boat to keep at the same angle to it. I got confused by "being headed" and "heading up," I think. Sorry Tannerz, the diagram still didn't help, but how cool is it that you can change it in a previous post!
     
  7. Chainsaw

    Chainsaw Brmmm Brmmm

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    A possible answer has been located.

    Unfortunately, is it so secret it has to go through official channels. LOL. :D
     
  8. madyottie

    madyottie Apprentice

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    I feel left out right now... I think I might be the only laser sailor left on earth not with a post on this thread!

    I'd like to state that I'm also an RYA Dinghy/Racing instructor, and for what its worth, having those qualifications doesnt mean we always know what we're on about!! You know what they say.... "those that cant do, teach" lol.

    I've owned 6 lasers, and dont think I've ever had one planing upwind. That said, I did borrow one from a friend and on one beat it absolutely flew, just breaking a plane from the leeward corner of the transom, for short periods, between sets of waves.
    I've tried everything I can think of to get mine to do it, and it just doesnt happen! :(

    On the subject of apparent wind and pointing higher....
    As the boat speeds up, the apparent wind moves forward, as in a heading shift, essentially forcing you to sail lower. you bear away, and your speed increases further, and it starts over again!
    ----------
    Food for thought...
    Then of course you get the extra leeway, which changes the angle of attack for the centreboard, which then starts to generate more lift to windward, which effectively creates a lifting shift!! help! way out of my depth here!
    Back to reality...
    ----------
    In a high performance skiff, like a 49er or RS800, the apparent wind shifts far enough that you often cant lay up to the mark on a broad reach, so the top guys will sometimes stall the kite (sheeted in until the boat stops) and then sail slowly using the true wind to get up to the mark. In these same boats, the difference in speed downwind means that twin wired boats can often sail faster and lower on the runs than the boats with only one guy on trapeze, due to the increased power, and hence apparent wind!!
     
  9. tannerz

    tannerz New Member

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    I am glad you got it. :) the diagram didn't make any sense to me until i started drawing all over it, then it made sense.

    Just took the laser out for a bit and did some practical stuff. Without competition sailing a set course, or instruments it is difficult to get any sort of true data, but I would pinch a bit when the speed came up, until it slowed, went down past polar a bit, picked up tons of speed and pinched again. The final result was that over distance the overall had me pointing higher overall than just sailing polars. I don't know if the VMG was better though... will try it out Monday night at the beer cans.
     
  10. Chainsaw

    Chainsaw Brmmm Brmmm

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    This is more or less what DrLaser says is so. You bear away momentarily and then headup. Here is the article:

    http://tinyurl.com/2przax"http://tinyurl.com/2przax
     
  11. gouvernail

    gouvernail Active Member

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    OK gang..I guess planing to weather is now the subject??

    A few years back when I weighed about 200 and was a LOT younger, I was fiddling with what I called the "Reach-o-Matic."

    There was a situation where I could briefly plane to weather.

    1. It took at leat 15 knots or so of breeze.
    2. The water had to be flat. NO WAVES

    There is a place on lake Travis where there is a hill and wind that wraps around the hill and then the wind spreads out onto the lake from the shore.

    So. the result is about 100 yards of close hauled available starboard tack sailing right up against a shore.

    I found that on certain days I could reach off a bit, get up on plane and then sort of stay on plane all the way up to close hauled. The guy who was sailing with me that winter was 6'3" and only about 175 and he could not get the leverage to accomplish the same deed.
    When teh reach-o-matic happened, I would shoot ahead about fifty feet in a very short distance.

    I had to hike on one leg, with the other leg in my lap and hold both arms straight over my head...so I didn't last long. Usually the wind would drop or I would need to steer a bit and I would end up teabagged.

    But WE both knew it was a very real form of planing to weather.


    I also think the game would be a lot more physical if winners had to hike hard enough to plane.

    OH yeah... Nick and Ed Monske weighed about 110 lbs each in the early 1980s. They rigged a trapeze with webbing attached to the sail sleeve just above the mast joint. They stood on the side and planed to weather a lot.

    Mostly, the hull does not have adequate displacement to allow a hiking guy to plane to weather.

    My hunch?? If we had 60 pound Lasers, the guys who currently win would be planing to weather in some conditions.
     
  12. viktor188924

    viktor188924 New Member

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    i wanna see this trapeze! and a laser weighing 60 lbs... ross?
     
  13. Chainsaw

    Chainsaw Brmmm Brmmm

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    Remember: vote ross.

    He has a lot of work to do. JC strap, 60lb lasers, trap webbing on sails...oh yeah and Carbon boweyes.
     
  14. Ross B

    Ross B Guest

    ehhhh, gotta keep the spirit of the origional design of the Laser there, traps kinda throws that out the window as an easy to sail boat

    and the boat weighing 60 pounds? I don't see that happening, if were to to improve building technique and use better lighter materials, I could loose some weight, but not more than half
     
  15. gouvernail

    gouvernail Active Member

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    you could build a 40 pound laser shaped boat with carbon fiber and the right molding machinery but:
    It would cost many many thousands of dollars
    It would tip over at the dock

    Such a beast certainly would not be useful to those of us who only want to sail in hundred boat fleets of equal craft.

    vote for Ross!!

    Back to the thread:

    I would guage the speed by using radar
     
  16. Chainsaw

    Chainsaw Brmmm Brmmm

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    When I was a kid, my old man had a knot gauge he threw off the back of his trailer sailer. It consisted of a clear plastic tube with knot markings on the outside and spring inside and an indicator. You dropped about 30m of line of the back off the boat. At the end of the line there was a round disc. As you increased speed, the drag on the disc increased. Inside the clear tube (tied to a cleat near the transom of the boat), you could see the indicator measuring the speed.

    Why don't we have something like that in lasers? Shouldn't be too hard to haul in 30m of line before the leeward mark rounding.
     
  17. Ross B

    Ross B Guest

  18. viktor188924

    viktor188924 New Member

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  19. Ross B

    Ross B Guest

    I would assume so

    but you can surly use it for training purposes

    better then the idea proposed by Saw's old man, and easier to use

    *no offense Saw
     
  20. kees

    kees New Member

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    I fully agree with many others that optimal speed can be found by feel, listen etc.
    For for the persons who want to have numbers, I'm using a Timex Speed and Distance watch. An advantage of a watch is that it's easy to read on any position of your body in your Laser.
    [​IMG]
     

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