Select to expand quote
All well and good, BUT. The original system was surely the best for calculating knots speed. Weren't knots tied in rope and let out the back of the boat?. The faster the "knots" were released, the faster you were going. I'm going to try this, does anyone know how far apart the knots need to be tied on the rope?
What type of rope ?
Is it soft and runs through your hands with ease and little friction.
Or harsh causing pain and nasty burning.
Do we consider stretch?
Manufacturers of this rope would have to standardise the product before offering it to our Knot grandmasters to get it knotted.
How far to do the knots?????
How long is a piece of string? I use from the tip of my nose to my index finger on my left hand.
Can of worms yet again 
Select to expand quotekato said..
All well and good, BUT. The original system was surely the best for calculating knots speed. Weren't knots tied in rope and let out the back of the boat?. The faster the "knots" were released, the faster you were going. I'm going to try this, does anyone know how far apart the knots need to be tied on the rope?
What type of rope ?
Back in my days as a lumberjack, before GPS, I solved the problem of the best rope.
Tie a stone on the end of the cotton, get up to speed, zero the meter, cut
the cotton at 1 minute. Do the sums.
( They probably still use hip chains in dense forest where GPS reception is poor. )
The 'chip log' method was a really old method used by sailors out at sea.they used this method to determine the ships speed.they tied a rope to the log & it had knots in it at 50 feet distances.they would throw it overboard .now here is when it gets interesting.a sailor would count the times the # of knots slipped through his hands.this would be counted diring the time it took for sand to fall through the bulb of a 'hour glass'.that time was calibrated to the time the elapse of 30 secs.for example if ten knots passed through the sailors hands in 30 secs.then they knew the ship was moving forward at the speed of 10 knotts.old 16th century method.Wow!
Bookmark this thread for future reference.
www.newscientist.com/article/mg21128294-300-mega-space-storm-would-kill-satellites-for-a-decade/
Select to expand quoteIan K said...
Bookmark this thread for future reference.
www.newscientist.com/article/mg21128294-300-mega-space-storm-would-kill-satellites-for-a-decade/
Wow ! Thought global warming was bad!
Select to expand quoteSparky said.. hardie said.. decrepit said..
Magic, your still not there, the point is, how inaccurate car speedos are.
It's not just a case of the extra decimal point, it's that you can't judge the accuracy of a gps by comparing it to a car speedo.
Because the car speedo can be out by 8% and we need much better than that, and typically if a gps has a good sky view it will be far better than a car speedo.
Mike what if you're really accurate at counting in your head like 1001 1002 1003..... 1022 and a bit, You could do a count for each run and say run1 was to a count of 22 seconds, and just a little bit more, etc then you calculate the distance you travelled with prior references to google earth, and use the distance by time method to calculate each run? For those with poor memories you could bring along a waterproof marker and waterproof paper, and write down each run, wouldn't that be at least the cheapest way to be involved in speedsailing? then all the money you saved in buying multiple gps's and batteries and electricity for charging, could be spent on fast fins, that would make you go even faster, meaning you would ending up counting less seconds per run 1001, 1002, 1003, ..... 1021 and no bits.?? You could even get really scientific with the count like saying in your head "thousand and one, thousand and two, thousand and three, thou". Stop Counting. Given there;s 14 letters in each count if you stop at "thou" thats 4/14's of a second, so it can be as accurate as you want it?
All well and good, BUT. The original system was surely the best for calculating knots speed. Weren't knots tied in rope and let out the back of the boat?. The faster the "knots" were released, the faster you were going. I'm going to try this, does anyone know how far apart the knots need to be tied on the rope?
It depends on the period of time you over which you count how knots are released. If it's an hour then the knots are tied every 1852 metres. If 1 minute, then every 30.867 metres. in the case of Hardies 22 seconds then every 1.49 metres. If 10 seconds, then every 3.087 metres. If 2 seconds, then every 614.5 millimetres.
So to record 1hr, 10 sec and 2 sec, we would need 3 ropes and 3 hour glasses of 1hr , 10 sec and 2 sec duration and a mechanism to release the role as soon as the hour glass is turned and mark the rope when the sand is emptied.
The sailor could then submit the marked ropes to the GPSTC as evidence of the speeds achieved.
Hardly a challenge
What's next, windsurfing with a sextant to determine the angle of attack?
Getting into some pretty deep weeds here.
Select to expand quotehardie said..
Mike what if you're really accurate at counting in your head like 1001 1002 1003..... 1022 and a bit, You could do a count for each run and say run1 was to a count of 22 seconds, ...
Before the days of affordable waterproof watches I used to count down to the start-gun in sailing-dinghy races in my head - after lots of practicing I could normally get to within 2 or 3 seconds accuracy over 1 minute (we usually had a 1-minute to go warning making it a practical method and I usually blitzed the field on the starts as I was good at counting in my head 
). Now just need to get used to judging distance and then we could use this to get speed. Or maybe easier to just judge speed directly? Or why not just measure speed (rounded down to the nearest knot) if there is a suitable device 
?
^ I don't get it. Why weren't there fifty edits in ten seconds? Why wasn't it in slow-motion?
I was actually able to absorb and enjoy the footage. Weird.
Excellent contribution to this thread Spotty!
Select to expand quoteevlPanda said..
^ I don't get it. Why weren't there fifty edits in ten seconds? Why wasn't it in slow-motion?
Here's the tricked up version.
That there shows exactly why we used to tie a lot of knots and use a lot of rope - for harness lines!
Select to expand quoteSpotty said..
That's impressive even by today's standards and more so because i bet the board wasn't as user friendly as today are! 
That Laird guy needs to attend a Guy Cribb clinic, he has his boom way to low....classic rookie mistake....;)
Select to expand quoteJohn340 said..
^^^^^ The spin out recovery at 2.25 is especially cool
Yep thought he'd had it then..
Select to expand quotegavnwend said..
Like Lairds jimmy lewis old slalom board.looks nice & narrow.
It's weird. Back in the 90's, all our general medium/high wind slalom boards were around 20" wide. Sailed everything from 15 knots up and 6m sail on them! (that was when the biggest sail one needed was around 6m!!). 20" is what a lot of guys call a 50cm 'speed board' these days!? Speed board? Really???
'Speed boards' back then were 12" (30cm) to 15" wide (37.5cm). No surprise then that I am quite comfortable these days on my Carbon Art 40cm.
Our largest slalom boards were 24" wide (58cm!) Most were under 22.5". Lots of things have changed. Now we use 70cm wide boards and 7.8m+ sails where we used to use 59cm boards and 6m sails. I sometimes wonder if that is really progress. 
But , yeah, we go faster now on the bigger stuff! 
I was there when that footage was filmed and got to sail with and watch Laird sail. So impressive to watch, Laird has no fear and just loved to be on the edge. There was this other bald bloke called Fred or something, he went OK too
RAF sails with not much twist like we have today, very small boards as Daffy said and some serious wind, swell and chop.
Those NP video days were so jjust unreal.
Select to expand quoteka43 said..
I was there when that footage was filmed and got to sail with and watch Laird sail. So impressive to watch, Laird has no fear and just loved to be on the edge. There was this other bald bloke called Fred or something, he went OK too
RAF sails with not much twist like we have today, very small boards as Daffy said and some serious wind, swell and chop.
Those NP video days were so jjust unreal.
Fred Haywood maybe.
Can anyone work out how fast they were going?
I had one of those NP RAF Speed 5.4 sails.. Put it on consignment in freo and never saw it again 
no coin either
Select to expand quoteAl Planet said..
That Laird guy needs to attend a Guy Cribb clinic, he has his boom way to low....classic rookie mistake....;)
more down haul to open the leach too?
I'm not sure but I think I went faster in chop years ago on my Sputnik 270 WC edition and 6.0m North twin cam Spectro or something. That thing flew on the bay in Melb, and put with so much punishment, big long jumps and a body that was 25 years younger. It used to love big lay down gybes (or so I remember). I think I'm a faster on the flat now, but not so in the chop being more careful with todays boards and the body.
Select to expand quoteIan K said..evlPanda said..
^ I don't get it. Why weren't there fifty edits in ten seconds? Why wasn't it in slow-motion?
Here's the tricked up version.
Boy that looked like fun! I was wishing I was - a better sailor / younger / fitter so I could sail fast in chop like him until I saw the high speed stack.. 
Hi,
Chop? Small waves created by wind and water obstacles, sort of big ripples with peak to peak distance between half meter to a meter, height between 20-100cm...
In around 20kt Swedish wind, with my 7,8 or 6,6 S-Type and my slalom board CA SL 70 110l, I roar around 26-28kts (over 10s) gps measured. When wind peaks up to 25kt, I go up to 29-30kt and it is faaaaassssssttttt...chop everywhere between 20-70cm. When the chop is squared...then not faster than 25kt...
Hope it helps
Plettil
There's some similarity to skiing in bumps, because you have to constantly pick a line. Only in the ocean the bumps are moving too! I think bumps are easier than chop, but I'm a better skier than windsurfer.
The interesting thing about chop and waves is that they rotate around themselves in a circular fashion. So if you see a big swell prop up and form a white cap, it will drop down and then its reverse side props up, that goes down and then the big swell pops up again. Judging where the big swell will reappear is a lot of fun. The chop/swells are often offset like bricks so finding a path so you don't end up sailing up the back of a big one can be a challenge too. When I used to do windsurfer slalom racing in the ocean I really enjoyed the concentration involved in reading the wind and waves.
