kdw wrote:
Ice shrinks by 10% when it melts...This must explain why all lakes are 10% bigger when frozen.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [kdw]
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This must explain why all lakes are 10% bigger when frozen.
Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese]
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stringcheese wrote:
Today, Superior Man in Duluth Long Course was ~400 meters long.It was AT LEAST 400 meters long. Having a swim course off by 25% is a little crazy, but we all did the same course. The conditions were perfect and it's probably one of the best swims you will find in the Midwest. Where else do you get to jump off a ferry in a super scenic area for <$200? Superiorman is a fantastic event. The bike course is awesome miles 10-47 and the run is just as scenic as the swim.
Re: Race Directors....Why is it so hard to accurately set up a swim course? [triathlete37]
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Quote:
For how far off superior man was for the swim the correct analogy would be, "would you be mad if the bike was 4 miles long". Every athlete including the elites in the midwest spent 10 plus extra minutes in the water because of poor race management. I'm pretty accepting and understanding of mistakes and everyone does the same course, but at some point it's too much and they need to understand they messed up.
Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese]
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Sometimes the anchors for the buoys don't quite hit the bottom, but even if it does, it's not like it's a sign post, the buoy is held by rope, which gives it many degrees of freedom to drift, and depending on the number of turn buoys, that can easily significantly impact the distance.
I have set swim courses before, and when we did, we used a laser sight to measure the distances, but it was a windy day, when we re-measured the next day for the races when the air was more still, there was a significant change in distances so we had to go out and move buoys (and in some cases, clip on a second anchor, to reduce the variation that wind/current could make) to make the distance accurate...
It's not like a run/bike course where you can calibrate a wheel and then wheel it out a few times to certify the distance... It's like trying to wheel out a course during an earthquake at the upper end of the richter scale...
But yes, in general (but especially on the swim) GPS is the bane of race director's existence... people don't grasp the error ranges on GPS and influencing factors, vs. measurement with a calibrated wheel or laser sighting...
I have set swim courses before, and when we did, we used a laser sight to measure the distances, but it was a windy day, when we re-measured the next day for the races when the air was more still, there was a significant change in distances so we had to go out and move buoys (and in some cases, clip on a second anchor, to reduce the variation that wind/current could make) to make the distance accurate...
It's not like a run/bike course where you can calibrate a wheel and then wheel it out a few times to certify the distance... It's like trying to wheel out a course during an earthquake at the upper end of the richter scale...
But yes, in general (but especially on the swim) GPS is the bane of race director's existence... people don't grasp the error ranges on GPS and influencing factors, vs. measurement with a calibrated wheel or laser sighting...
Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese]
[ In reply to ]
While I get what you would like, I miss the early days of Triathlon when we were there to do our best. Distances were what ever fit.
As sports grow, more rules are imposed as competition grows.
I never worry if I swam 1:30per 100 after a race. I know many in my age group and look how I compared.
Like Monty ALWAYS says, look at the pro swim times and you get an idea if the course was close to accurate.
Team Zoot So Cal
As sports grow, more rules are imposed as competition grows.
I never worry if I swam 1:30per 100 after a race. I know many in my age group and look how I compared.
Like Monty ALWAYS says, look at the pro swim times and you get an idea if the course was close to accurate.
Team Zoot So Cal
Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese]
[ In reply to ]
I used to do this Oly race series over a number of years, put on by the very same race outfit at the same lake at the beginning, middle, and end of summer ~ so a sample size of probably at least 6-8 swims (didn't do all 3 every year) which theoretically should have all been virtually identical (it's a well-developed urban lake w/ both residential & park frontage, so no tidal swings and maintained at a pretty steady pool level, not like a seasonal irrigation reservoir). As a long-time swimmer, my form/performance was pretty consistent, which I could verify doing 1650y time checks in the pool which rarely deviated from 23 minutes, +/- about 30sec depending on where my training was at during the season. Over the course of those different lake swims, my time variance was 7(!) minutes, from a low of 17 (fastest out of the water that day was 13-something, which of course is substantially faster than the 1500m WR) to a high of 24. That's a range of approx 33% given a rough avg of 21 min.
I certainly don't expect extreme precision, but that much variation from an experienced race organizer under about as stable an open-water setting as any I've ever seen (wind is about the only real wild card) seems ridiculous.
I certainly don't expect extreme precision, but that much variation from an experienced race organizer under about as stable an open-water setting as any I've ever seen (wind is about the only real wild card) seems ridiculous.
Re: Race Directors....Why is it so hard to accurately set up a swim course? [OneGoodLeg]
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You'll need a compass and an accurate map/chart to but anyone who know what this is could lay out, and set, an accurate course in their sleep.
Re: Race Directors....Why is it so hard to accurately set up a swim course? [davidalone]
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davidalone wrote:
Have helped set up a couple of swim courses for university opwn swim and aquathlon events; heres some reasons why swim courses are tough: 1) where does the swim course 'start' exactly? Most competitions are beach starts. Does your swim course start at the start gate? Or the water itself? Thats easily 10-15 meters right there (dont forget the water moves with the tides). What if you set up your course at low tide and the tide starts to come in?
2) most bouys are set up by canoe or speedboat, typically via gps. First you have to account for gps error (easily 10 meters) , then you have to account for the fact that stopping a small boat in a precise location is not an exact science. Dont forget that most people arent exactly using military or fishing grade gps sensors and are volunteers.
3) the bouys are typically dropped via small anchor (they arent tied or secured to the sea bed, no one has that much money to get a diver to do that. ). Strong currents and tides can absolutely move bouys. We had to stop a race in between waves once as the bouys had drifted off a pretty big distance. Even in the event of relatively calm waters, a bouy can still 'float' in a circular radius of error (think of a force triangle- the point is a fixed anchor, the buoy is conmected to the anchor via a rope. However, the buoy can still be pushed off course by as much as the length of the connecting rope)
4) I have done races where the all the buoys are connected to the beach and anchored via ropes. This is a slightly better method and mitigates some error caused by 'floating' but ropes also expand when wet. This may not sound like much, but if you have a Loooong rope (say 100m), a small error can be pretty big.
5) unless you have a big race like ironman, beach use licenses typically mean most buoys are set up on race morning in the wee hours, in the dark. This is no fun and absolutely adds to the stress.
I believe you can buy nylon rope that does not expand when wet, which if used would make this method very accurate. The Acworth Oly Dist Triathlon, just outside of Atlanta, used this method for several years, with 1 gallon milk jugs tied to the rope every 5-10 yards such that you more or less had a continuous "lane rope" for the whole swim. IIRC, it was a straight 825 yd out and back with the rope tied off at the beach and at the turn-around boat. Not sure if that race is still going on now but that was a pretty accurately measured course and, once you get your nylon rope and jugs set up, you can use the same set-up for years to come.
"Anyone can be who they want to be IF they have the HUNGER and the DRIVE."
Re: Race Directors....Why is it so hard to accurately set up a swim course? [ericmulk]
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I don't think this is accurate. Nylon at the molecular level has hydrophillic groups and absolutely does absorb water. lots of marine ropes have water resistant coatings but these are never 100%.
Re: Race Directors....Why is it so hard to accurately set up a swim course? [davidalone]
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davidalone wrote:
I don't think this is accurate. Nylon at the molecular level has hydrophillic groups and absolutely does absorb water. lots of marine ropes have water resistant coatings but these are never 100%.IIRC, the way the Acworth team set it up, they measured out a 750 meter length of rope, tied the milk jugs on every 5-10 m, and then strung the rope out across the lake from the beach to a boat anchored 750 m from shore. Rope was taut at the beginning and, if the rope did expand, it was tied to the boat and firmly anchored. They set the swim course up the afternoon before the race and left it up overnight.
"Anyone can be who they want to be IF they have the HUNGER and the DRIVE."
Re: Race Directors....Why is it so hard to accurately set up a swim course? [ericmulk]
[ In reply to ]
We run our events in the local river, it's really great for measuring the lineal distance, but with the current assist it's not really swimming 750m or whatever the length is.
If we get it right with tides and river current, the gun swimmers can smash it out in about 4 minutes :)
If we get it right with tides and river current, the gun swimmers can smash it out in about 4 minutes :)