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Race Directors....Why is it so hard to accurately set up a swim course?
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My last two races both had noticeably long swim courses.

Two weeks ago, Cleveland AGN Oly was ~200 meters long. Today, Superior Man in Duluth Long Course was ~400 meters long.

The GPS track on my Garmin can tell me what side of the path I was running on

I'm not complaining, but as someone who's never had to set up a course, I'd be interested in what makes it so hard to accurately layout a swim course..

"Good genes are not a requirement, just the obsession to beat ones brains out daily"...the Griz
Last edited by: stringcheese: Aug 26, 18 21:47
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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stringcheese wrote:
My last two races both had noticeably long swim courses.

Two weeks ago, Cleveland AGN Oly was ~200 meters long. Today, Superior Man in Duluth Long Course was ~400 meters long.

The GPS track on my Garmin can tell me what side of the path I was running on

I'm not complaining, but as someone who's never had to set up a course, I'd be interested in what makes it so hard to accurately layout a swim course..

(not a race director)

Your question already contains the answer: the 200m and 400m you mention are just numbers on your Garmin, and have relatively little to do with the distance you swam.
I once saw a swimtest with two identical watches which gave hugely dividing results.
Gps works on land, but not while swimming.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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I've only set up one swim course but the range on Garmin's is pretty ridiculous.

I set up my course with a laser range finder with a Garmin as a back up. Both of them had the loop at 750m.

I saw Garmin's from athletes ranging from 600 to 850.

ITU regulations state the swim course should be within 10% accuracy so anything between 675/825 is still "perfect" for a 750m loop.

Additionally, maybe you lay a bouy with anchor and think you have enough rope but you didn't hit the bottom with it, now the current or tide is moving everything.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [jarret_g] [ In reply to ]
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Tide/currents make a huge difference. I raced an Oly once where, between the first AG wave at 7:30 and the Elite wave at 9:00, the course went from ~1250 to ~1700 (extrapolating from swim times of known-good swimmers and Garmin averages) because the anchor didn't quite reach the sea floor. Some of the Men's 18-39 wave thought they were good enough to be Elite based on their swim times that day...

ZONE3 - We Last Longer
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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If you want your Garmin to be more accurate, you'd need to put it under your swim cap. Still not perfect, but A LOT better than on your wrist, where the margin for error is ridiculously huge.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [longtrousers] [ In reply to ]
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longtrousers wrote:
stringcheese wrote:
My last two races both had noticeably long swim courses.

Two weeks ago, Cleveland AGN Oly was ~200 meters long. Today, Superior Man in Duluth Long Course was ~400 meters long.

The GPS track on my Garmin can tell me what side of the path I was running on

I'm not complaining, but as someone who's never had to set up a course, I'd be interested in what makes it so hard to accurately layout a swim course..


(not a race director)

Your question already contains the answer: the 200m and 400m you mention are just numbers on your Garmin, and have relatively little to do with the distance you swam.
I once saw a swimtest with two identical watches which gave hugely dividing results.
Gps works on land, but not while swimming.

Swim courses aren't set up by the swim GPS readings from a watch.

There were multiple GPS readings of the Cleveland course. None had the distance correct. All were long

"Good genes are not a requirement, just the obsession to beat ones brains out daily"...the Griz
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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I would guess because there is no accurate way to measure things. It’s why I laugh when I hear people wanting Course certifications in tri. It’s easy to certify a run or bike course because there are far more accurate options to get the accuracy super detailed. Doing it on water using gps or range finders will greatly increase inaccuracy because of the inaccuracies in both technologies and human application of said technology. Now I don’t think it’s to the magnitude of what 15% inaccurate but it’s damn hard to get a absolute true measure in an marine environment and then being able to “measure it”.

Every race I go to I range find distances to the 1st turn buoy to find the shortest distance for my athletes. In a straight line start I easily see distances of at times even 8-12m difference. So do that a few times and suddenly your at 30-40m long or short etc.

Brooks Doughtie, M.S.
Exercise Physiology
-USAT Level II
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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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.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [davidalone] [ In reply to ]
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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.

Thanks for your insight....makes sense.

"Good genes are not a requirement, just the obsession to beat ones brains out daily"...the Griz
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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The biggest inaccuracies in swim courses measurements are athletes believing their “Garmins” measure the course accurately when half the time it is submerged underwater, athletes thinking they swam the course perfectly straight and an athlete’s ego not liking the time they swam so the course had to be long.

http://www.magnoliamasters.com
http://www.snappingtortuga.com
http://www.swimeasyspeed.com
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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While I have no knowledge or insight on Cleveland, I was at Superior Man yesterday and have helped set this event up in the past. As for the why the swim course was long this year, your guess is as good as mine. The swim course director was new this year and when I talked to the race director before awards, he said they were using the coordinates from last year.

As far as other people commenting about how hard it is to setup, and you do not know it was long based on your GPS...

1) this course is parallel to a break wall. You literally could measure out the long legs on land (they literally place a couple lifeguards on the breakwall it is so close) and the only variation would be the two short legs of the rectangle... Should be a very easy course to measure well and place buoys. Yes, you need to get them to stay put, but yesterday at least the lake was very calm and the buoys did not move due to heavy waves or current action.
2) I was doing the race as a relay, and every one of us was wondering what was taking our swimmers so long. After the race every athlete I talked to that had a GPS had a similar measurement of 2800 yards for a half iron. I then went and asked the timing guy to get me the swim times of the lead folks. Sure enough, guys who regularly swim more in the 30 flat range had 35-37 minute swims. So, yes I understand that a GPS is not extremely accurate in water, but all of those pieces of information point to a significantly long swim.

Bottom line, the course at Superior Man was very long this year. Both courses... 600 yards extra in a half and the short course, which was supposed to be 1/2 mile was nearly a full mile from everything I gathered on that.

Ryan
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [SnappingT] [ In reply to ]
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I wouldn't know about that there. Your Garmin should always read longer, specifically because none of us swim in a straight line in the open water. I'm not good at OWS when it comes to sighting and have swam 500-700m extra twice.

Washed up footy player turned Triathlete.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [TheStroBro] [ In reply to ]
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I live on a lake that freezes in the winter. On the ice I measured exactly 100 yards, drilled holes with an ice auger, lowered 2 bricks painted white in about 8-12 feet of water. In the summer I have a yellow rubber coated steel 1/4 inch cable on the bottom of the lake between the two points. My garmin consistently says 92 or 88 yards between the two points.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [endosch2] [ In reply to ]
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Interesting.

Washed up footy player turned Triathlete.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [SnappingT] [ In reply to ]
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SnappingT wrote:
The biggest inaccuracies in swim courses measurements are athletes believing their “Garmins” measure the course accurately when half the time it is submerged underwater, athletes thinking they swam the course perfectly straight and an athlete’s ego not liking the time they swam so the course had to be long.

I resemble the "ego" part of the above :-(

I always chalk it up to everybody has to do the same distance (what ever that is).

So...

Winner winner, chicken dinner.

I saw this on a white board in a window box at my daughters middle school...
List of what life owes you:
1. __________
2. __________
3. __________
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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It might not be as easy as it looks ;-)

Even for pools, USA Swimming puts out a 22 page guide for measuring and certifying pool dimensions. For certain levels of record performances, the pool has to be measured and certified by a professional surveyor or engineer before any conditions change (i.e. a bulkhead is moved.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [STP] [ In reply to ]
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Would you complain if the bike course was 200-400 meters long?
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [triathlete37] [ In reply to ]
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triathlete37 wrote:
Would you complain if the bike course was 200-400 meters long?

We are triathletes... doesn’t that mean we complain about everything, especially on ST?
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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Race directors generally don't set their swim courses... it's a delegated task to a person or group of people tasked with swim course related duties. Sometimes coordinated with a local sherfiff boat or someone with a small craft... sometimes set with kayak loaded with cinder blocks/rope/towing buoys... can be a challenge. It's not like spray chalking a sidewalk.

Setting a swim course can be a challege due the environment. Depth, tides, currents, waves, wind, boats/jetskis/etc., make setting a nice swim course a bit of a challenge.

I was at Cleveland and agree it was probably long... the devil in that detail is that with waves spread over 2+ hours is some people had much different swimming conditions. Even in the best conditions of the first wave the first swimmer hit the beach at 24'sh minutes... that was clue #1.
Last edited by: xeon: Aug 27, 18 11:32
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [xeon] [ In reply to ]
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I’ve never set a swim course, but here are some thoughts.

Yes, marine GPS and depth finders are very accurate. You should be able to get a precise Geo coordinate to know where a buoy belongs.

The tough part is securing it to the bottom. When anchoring a boat, you need a substantial amount of “scope” on the line, so that the anchor is set and pulled diagonally from the boat on the surface.

If you read the depth finder and saw it read “30 feet”, you wouldn’t just drop that much line. Depending on the wind, current, tide, anchor weight, floating object size, you may need as much as 90 feet of scope (for a big boat, for example). Having 30 feet of line wouldn’t allow the anchor to grip, and it would drag across the bottom.

Bottom line, you need someone pretty experienced with the local conditions and with basic mariner skills. Some guy that just throws over the anchor, waits for it to hit bottom, and then ties it off there, is going to screw up.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [endosch2] [ In reply to ]
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 On the ice I measured exactly 100 yards,

---------

Did you wheel measure it or gps measure this?

Brooks Doughtie, M.S.
Exercise Physiology
-USAT Level II
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [triathlete37] [ In reply to ]
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I've been on several courses where the bike is a 1/2 mile long, or the run is .2 Miles short...hell, there's a lot of 5Ks under 3 miles...this isn't hard.

Washed up footy player turned Triathlete.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [B_Doughtie] [ In reply to ]
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B_Doughtie wrote:
On the ice I measured exactly 100 yards,

---------

Did you wheel measure it or gps measure this?

I used a construction site super long reel measuring tape.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [stringcheese] [ In reply to ]
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My watch GPS is sometimes great and often useless. I train in a rowing lake that has submerged metal frame of 1000m. I can follow perfectly straight (like watching a lane line under water) my watch has has a 50 percent error at times.
I keep my watch on my wrist for hitting the lap function but I ignore the distances.
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Re: Race Directors....Why is it so hard to accurately set up a swim course? [endosch2] [ In reply to ]
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Ice shrinks by 10% when it melts...
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