frant said...

What are the GPS TC rules and GPSSS rules on postings from GPS units. Since purchasing a GT-11 I like most others have been wearing both units on the water. For the GPSSS site I have been posting the GT-11 doppler results. Have done the same on the GPSTC site. This is fine when I am "competing" with myself only, add the competitive challenge of the GPSTC and I find myself looking for every (fair?) advantage. My Feb 12 session Ave 10 sec GT-11 33.32, Foretrex 33.42. GPS max GT-11 35.2, Foretrex 35.4. Nautical mile 29.5 vs 29.64.
I will stick with doppler but then MAYBE!!!
Ruling please.

Frant, GPSTC is looking at 2009, for standardising GT-11 and Doppler as the unit and method of posting for top 10 teams and individuals, the fun teams and indivuduals, who aren't top ten can use Garmin's and Track Points.

The latest talk for this year, has been for the top ranked guys to use Doppler for everything except Alpha 500 where it appears Track point is more accurate. Track Point for this year is OK to use, but you just have to be consistent and use the one method till the end of year, however, once you start using Doppler, not fair to go back to Track Point.

What happens if an individual cannot afford a Navi??
Seems like a lot of sailors in the GPS challenge already had or bought Garmins etc before the Navi came out.
So if you are an average punter or even a hot shot and see this as being a tad unfair having to conform what do you do??
No offence to anyone but wasn't and isn't the original concept to get ANYONE out on the water and competing??

There's always the possibility, of deducting the average difference between track point and doppler in each category.
As said it's not for sheep stations, and I think an agreed upon "trackpoint penalty" would be fair to all.

elmo said...

I don't lose any sleep over what GPS people use or whether its trackpoints or doppler as long as it's straight up.

The whole thing is an excuse to go for a fang with your mates

I agree, and lot's of people have bought Garmin's and don't have the finances to swap over, so Garmin's are in.

I agree with just about everything that has been said here!!

1 - Its all about participation and getting out there for a fang with ya mates!

2 - Garmins have to be in!

However - I agee wholeheartedly with Decrepit for the 2 second category!!

There are potentially significant differences between Navi and Garmin for the 2 sec. For instance I had a Navi 2 sec of 41.1 and a Garmin 2 sec of 42.7 for the December 30 'big day' at Hardies. In fact my top 3 Garmin 2 secs were above the Navi 2 sec and they occured on somewhat different runs to the Navi 5 x bests. The techos can tell us why. Yoyo has the track!

I understand that GPS SS is going to apply a 'factor' to all garmin speeds so that as much as possible we are comparing apples with apples. I dont see the need for GPS TC to go this far - except for addressing the 2 sec variations which can have a significant bearing right through the rankings for this category. Maybe we can use the GPS SS factor as the 2 sec 'normaliser'. Maybe we can apply our own.

Is this actually possible Ben / Hardie - not wanting to cut across the grain here!
Keep up the good work guys - we are all indebted - but I think this one needs a little attention in the interests of the Challenge!

There is no problem with the site doing it. Think of the site as your magic genie who can do anything. I'm quite prepared to spend a day coding a new function if it will save a day's calculation for the people out there... and mostly the ratio is more like 1 hour of my time saves years of people-time when you think of how many people use the site.

So ask and ye shall receive!

My one overriding concern is making the site easy to use for newbies. The experts are usually prepared to jump through hoops, but it's the newbies that make the site interesting, so I'm not going to compromise the ease of use.

Personally I can't see how 0.2 of a knot makes any difference, but I'm prepared to accept that other people see this as important. I'm also prepared to code in any changes that people want, so long as it's generally agreed on as a good thing.

If someone can come up with an easy way of resolving this problem, I'm all ears!

Does it really matter this much.

People worrying about a unit or calculating methods giving someone a 1/2 knot advantage is not what this challenge is about, leave that to GPSSS.

This kind of discussion and the applying of Handicaps to others is part of the reason why I was hesitant to start the teams thing in the first place.

This is a "Social Challenge" the day we start applying fudge factors and making people change the equipment they can use will be the death knell of the Challenge and that will be a sad day indead.

If you want precision and all that other serious stuff then register with GPSSS and start posting there.

The first rule of GTC

You have fun

The second rule of GTC

You have fun with your mates

Anything after that is static and relatively minor



Theres another rule

If it ain't broke, don't furk with it

Fun and Fair aren't mutually exclusive...

So let's simplify the problem.
* Units that only record trackpoints (such as Garmin) tend to read higher (on 2 sec and 5x10) by a small percentage.

Is this right?

Now let's consider the implications:
To make this totally fair and not disadvantage the garmin users, we have to know by how much. Can someone point me to a formula that will calculate this value?


Also, let's not forget that doppler tends to read higher for Nautical mile, 1 hour and distance...

Can of worms

One way to deal with this is for people to either nominate or tick a box whether they are using track point or doppler.

Then when someone who has just posted a 2 sec 40.1 in Doppler, and a fellow competitor posts a 2 sec 41.0 in track point, the Doppler user can say to themselves I can deduct 1 knot off that, so I'm faster 40.1 vs 40.0.

That same Track point user who just posted a NM 29.5 versus the Doppler user's NM 30.0, can say to him/herrself, well I'll deduct .7 off that Doppler NM, so I'm faster 29.5 vs 29.3.

So people can do it in their heads. Remember no sheep stations here, and it's all about fun, fun fun, let's not lose sight of that or people will start taking their spade and buckets back home with them and won't play with us anymore, coz we got too elite, and we dont want that because it happened to windsurfing in the past, we're just rejuvinating some interest, let's not stuff it up!!!!!

hardie said...

One way to deal with this is for people to either nominate or tick a box whether they are using track point or doppler.

Then when someone who has just posted a 2 sec 40.1 in Doppler, and a fellow competitor posts a 2 sec 41.0 in track point, the Doppler user can say to themselves I can deduct 1 knot off that, so I'm faster 40.1 vs 40.0.

That same Track point user who just posted a NM 29.5 versus the Doppler user's NM 30.0, can say to him/herrself, well I'll deduct .7 off that Doppler NM, so I'm faster 29.5 vs 29.3.

So people can do it in their heads. Remember no sheep stations here, and it's all about fun, fun fun, let's not lose sight of that or people will start taking their spade and buckets back home with them and won't play with us anymore, coz we got too elite, and we dont want that because it happened to windsurfing in the past, we're just rejuvinating some interest, let's not stuff it up!!!!!

Does it really matter when its only half a knot difference? The K.I.S.S. principle applies, keep it simple stupid! As soon as it gets the slightest bit complicated you will lose participants, it's already happening with the GPS SS and will only get worse once they have gold members and different sites for different levels of members. Going fast is all about fun, keep it that way and make it easy to be involved.

Fun….yes it’s all about fun, but what’s fun? For a lot of people, me included, fun is the competitive aspect. A lot of people, whilst they might not say so, are in fact EXTREMELY competitive.

Fun is going out for a sail with a group of sailors whose speeds are generally similar, or maybe just a bit better, and finding out that I beat them that day, by 0.2 of a knot or whatever. It’s not that fun when one of them, because they happen to have a Garmin, pulls another knot out of their arse afterwards.

I fully acknowledge that Garmins need to be in the challenge, but like it or not, the “Garmin factor” is a real pain, and towards the pointier end of the scale, and most particularly in the 2 second category, I think it needs to be addressed. I say figure out just how much the Garmin factor is, and lop it straight off the top of the 2 second peak every time.

That is fair, and fair is fun.

I understand what you are saying AUS1111. Here I get sailors adding the Garmin factor to the speed on the screen. I had one guy say he did a 43 when I could see his screen said 40. He said he was calculating the fact that the trackpoint speed was always higher than the screen reading and adding in his own conversion. He even posted it on GPSSS! Does it matter, not really, the cream always rises to the top and the fast guys will always be fast regardless. Could have dobbed him in and had the speed removed but what's the point, we're all responsible for our own actions regardless of how competitive we are. To me it's all about the thrill of speed and the fun I have going fast, don't really care what speed anyone else is doing, the race is against myself.

What I like about the Garmin is ease of use. If I just want to go for a quick fang and see my top speed that's all I take, dont even bother downloading the data. It's small, simple and pretty accurate for all my basic needs. Sometimes I "roo" the day I discovered the NAVi and introduced the speedsailing world to it.

I know very little about the X and Y accuracy of either the NAVi or Garmin units. I am guessing the accuracy of a particular reading has a potential error of between 0 and 5 m. This might lead to a confidence of (say) 10% to a sailors actual location being within 0.1 m (or even 1 m) of where the GPS recorded the sailors position and a confidence of (say) 99% that the sailor was within 5 m of the recorded location. I dunno, I know little about the accuracy of these devices... However, if this is the case, no matter how fancy the processing (whatever doppler is), the difference is not really relevant as the margin of error in the recorded data would seem to be more of an important factor then the model of device and the processing of the data... Or, is there something I am completely missing