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35 MPH on a Kona One
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KevinDo



Joined: 02 Jul 2012
Posts: 408
Location: Cabrillo Inside

PostPosted: Tue Oct 08, 2013 12:06 pm    Post subject: Reply with quote

konajoe wrote:
100% with KevinDo on this.

The wind was 16 G 22 mph the day I went. My average speed was nowhere near the max.

Using a gps with the gps-speedsurfing software can be pretty fun and educational for speed junkies. You can plot your data and see exactly where and when you get big speeds. It's also nice to be able to wear the gps so that you can see your numbers while you're sailing. If you have to put the gps in your pocket and if you don't have the plotting software, you'll have to guess where and when you were going fast. And your guess will most likely be wrong.


Don't forget speed genie! It can be a very useful tool on the GT-31 Very Happy
I'm more of a data junkie than a speed junkie so I analyze each session using this overlay I made awhile back. It's for the wind at the best angle for CB inside.

-Kevin



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2014 Cabrillo Beach GPS CS (inside)
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whitevan01



Joined: 29 Jun 2007
Posts: 469

PostPosted: Tue Oct 08, 2013 4:30 pm    Post subject: Reply with quote

GPS speed sailing is fun, but I take the numbers with at least one grain of salt. remember, if you are going with the tide, the GPS speed will be the tide speed higher than you're actual speed through the water. opposite will happen if going with the current. going across current, your GPS speed will still be a touch higher than actual speed through water.
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KevinDo



Joined: 02 Jul 2012
Posts: 408
Location: Cabrillo Inside

PostPosted: Tue Oct 08, 2013 5:01 pm    Post subject: Reply with quote

whitevan01 wrote:
GPS speed sailing is fun, but I take the numbers with at least one grain of salt. remember, if you are going with the tide, the GPS speed will be the tide speed higher than you're actual speed through the water. opposite will happen if going with the current. going across current, your GPS speed will still be a touch higher than actual speed through water.


Not understanding what you mean?

If Usain Bolt were to run into a headwind would a GPS placed on him be a tad bit slower than his actual speed?

Or you just trying to say that peoples speed aren't comparable due to different conditions on each day? Most of the times I'd prefer to speed sail in an ebb tide at my home spot as it's pretty flat than.

Not trying to be argumentative just trying to understand what you meant Very Happy

Regardless, GPS sailing is meant to be fun and in the end we are all just trying to beat our mates in pure speed Very Happy

-Kevin

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spennie



Joined: 13 Oct 1995
Posts: 811
Location: Thousand Oaks, CA

PostPosted: Tue Oct 08, 2013 6:54 pm    Post subject: Reply with quote

KevinDo: He's saying that a GPS records your speed relative to the planet, not the water you're on. If you're sailing with a current (in the same direction as the current), your GPS wil show higher than your actual board-on-the-water speed. If you're sailing against a 4-knot current, your board-on-the-water speed might be 34, but your GPS would say 30. You only get a true reading if you're on still water, say a lake.
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KevinDo



Joined: 02 Jul 2012
Posts: 408
Location: Cabrillo Inside

PostPosted: Tue Oct 08, 2013 9:34 pm    Post subject: Reply with quote

spennie wrote:
KevinDo: He's saying that a GPS records your speed relative to the planet, not the water you're on. If you're sailing with a current (in the same direction as the current), your GPS will show higher than your actual board-on-the-water speed. If you're sailing against a 4-knot current, your board-on-the-water speed might be 34, but your GPS would say 30. You only get a true reading if you're on still water, say a lake.


I still don't see why it should be taken with a grain of salt though? If you are comparing numbers from different days than yea they aren't really comparable. But for the guys who are really into it are usually there on days where conditions are similar to other "top" days.

Also how come you never use the quote function?? Very Happy
-Kevin

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spennie



Joined: 13 Oct 1995
Posts: 811
Location: Thousand Oaks, CA

PostPosted: Wed Oct 09, 2013 9:01 am    Post subject: Reply with quote

KevinDo wrote:
spennie wrote:
KevinDo: He's saying that a GPS records your speed relative to the planet, not the water you're on. If you're sailing with a current (in the same direction as the current), your GPS will show higher than your actual board-on-the-water speed. If you're sailing against a 4-knot current, your board-on-the-water speed might be 34, but your GPS would say 30. You only get a true reading if you're on still water, say a lake.


I still don't see why it should be taken with a grain of salt though? If you are comparing numbers from different days than yea they aren't really comparable. But for the guys who are really into it are usually there on days where conditions are similar to other "top" days.

Also how come you never use the quote function?? :D
-Kevin



Also how come you never use the quote function?? :D

Because the Quote function takes the whole post, so if you just want a bit you have to edit the rest out. Copy & paste is easier. I never use emoticons, either, think they're lame. Sorry.

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Sailboarder



Joined: 10 Apr 2011
Posts: 409

PostPosted: Wed Oct 09, 2013 1:10 pm    Post subject: Reply with quote

KevinDo wrote:
Sailboarder wrote:
konajoe,

How much wind was required?

My personal best are unrecorded, but repeated maybe 5-6 times. In 28-30 kts gusts (windmeter close-by), perfectly flat water with an Ezzy 7.5 and 46 stock fin. I'm 220 pounds and the fin was lifting me out of the water. Anyone has a clue about the speed I was going?


Can't really judge by those variables... Sad Should be noted though that what feels fast usually doesn't translate to fast numbers on the gps!

-Kevin


I agree that I will never know when I'm really fast without a GPS and I also agree with your note. In fact, I was possibly faster in similar conditions with my 40 cm fin. However, I assume the wall I hit with the longer fin (unbearable lift) must happen at a specific water speed with my setup.
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KevinDo



Joined: 02 Jul 2012
Posts: 408
Location: Cabrillo Inside

PostPosted: Wed Oct 09, 2013 2:24 pm    Post subject: Reply with quote

Sailboarder wrote:
KevinDo wrote:
Sailboarder wrote:
konajoe,

How much wind was required?

My personal best are unrecorded, but repeated maybe 5-6 times. In 28-30 kts gusts (windmeter close-by), perfectly flat water with an Ezzy 7.5 and 46 stock fin. I'm 220 pounds and the fin was lifting me out of the water. Anyone has a clue about the speed I was going?


Can't really judge by those variables... Sad Should be noted though that what feels fast usually doesn't translate to fast numbers on the gps!

-Kevin


I agree that I will never know when I'm really fast without a GPS and I also agree with your note. In fact, I was possibly faster in similar conditions with my 40 cm fin. However, I assume the wall I hit with the longer fin (unbearable lift) must happen at a specific water speed with my setup.


It is possible that the wall could be the same but too many variables in my opinion. I have always used the smallest fin possible (big sail/small board and fin combo) so I haven't really tested if hitting the "wall" was at the same speeds. Either way as long as your having a blast at those speeds than your set! Very Happy

-Kevin

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konajoe



Joined: 28 Feb 2010
Posts: 149

PostPosted: Wed Oct 16, 2013 9:42 am    Post subject: Reply with quote

Yes, results need to be taken with a "grain of salt". Noisy, unfiltered gps's with no firmware or software to remove outliers can give big false max speed numbers.

Unlike postings to gps-speedsurfing.com, postings to forums don't need to be validated. Once, a guy from Austin posted a really big day to the gps site. Someone eventually noticed that, when they put the overlay on google maps, his big speeds were achieved on dry land. Yep, he left his gps on during the drive home.
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KevinDo



Joined: 02 Jul 2012
Posts: 408
Location: Cabrillo Inside

PostPosted: Wed Oct 16, 2013 2:22 pm    Post subject: Reply with quote

konajoe wrote:
Yes, results need to be taken with a "grain of salt". Noisy, unfiltered gps's with no firmware or software to remove outliers can give big false max speed numbers.

Unlike postings to gps-speedsurfing.com, postings to forums don't need to be validated. Once, a guy from Austin posted a really big day to the gps site. Someone eventually noticed that, when they put the overlay on google maps, his big speeds were achieved on dry land. Yep, he left his gps on during the drive home.


Posting on GP3S does not necessarily remove spikes/peaks from your SBN or GPX as it uses the GPSresults engine. There is still a bunch of folks who post odd sessions. Regarding the FT gps, spikes are possible and not aware of any firmware. The GT-31s still calculate speed the same way with all 3 available firmwares. Still recommended to use Tom Chalko's firmware as it offers a lot of great features! Such as customized speed genie screen options!

-Kevin

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