GPS readings, true or false!

[Steven Vaccaro]

Back to the gps debate. I ran a jae rigger about 2 weeks ago. With the gps on top I got a speed of 70 plus mph. Now I knew it was fast, BUT NO WAY 70mph fast with the ul1 motor. Tossed it back in and pulled off some speeds runs in the 49-51mph area. Much more of what I was expecting. So be warned, not every reading on a gps is correct!

[Doby]

Any GPS readings I post are confirmed with at least 3 runs. Plus the GPS is usually on in the car on the drive to the pond so I can see if its close to my car's speedo.

The purists will say that unless its a formal SAW type of set up for recording speeds, GPS's can't be relied on, but for me, its close enough as a few MPH here or there is pretty minor.

[H2OCamel]

That's why I use both gps and radar for backup confirmation

[Steven Vaccaro]

Any GPS readings I post are confirmed with at least 3 runs. Plus the GPS is usually on in the car on the drive to the pond so I can see if its close to my car's speedo.

The purists will say that unless its a formal SAW type of set up for recording speeds, GPS's can't be relied on, but for me, its close enough as a few MPH here or there is pretty minor.

I agree, I can run 3 or 4 times and get readings very close. Close enough that I can use the gps as a tool for tuning. The 70mph was a strange fluke. But I can see something like that happening to my son and then saying "dad at the pond today I ran 70mph, check out the video I posted on youtube!"

[millzee]

how accurate is the gps on the eagle tree?

[Steven Vaccaro]

That's why I use both gps and radar for backup confirmation

With a radar, do you have to have the object coming straight at you?

[AlanN]

GPS can be waaaayyy off. Especially when quick turns or any other fast change in direction are performed. Radar is the best way to go for accuracy.

Steve,
Yes, at least approximately straight at you.

[H2OCamel]

+/- 6* works on my bushnel, straight on is best but carbon fiber boats like my oval master 29" are stealth boats to radar!Not friendly to GPS either.

[6sHyper]

Just like Doby said, i think the main thing in being as accurate as possible with GPS is to do at least 3 runs, its pretty obvious when you get a reading thats way off, i had a 100mph reading once, but other than that every reading has been within 5mph i would say, and for me thats plenty accurate for exactly as Steve mentioned, tuning.

[H2OCamel]

With a radar, do you have to have the object coming straight at you?

Steven I just make sure to turn before it gets to me

[Steven Vaccaro]

Steven I just make sure to turn before it gets to me

So you drive and hold the gun? You are the man!

[H2OCamel]

So you drive and hold the gun? You are the man!

And video it and still photos too!!

It helps to have a radio that fits your hand well enough to drive one handed

[Steven Vaccaro]

And video it and still photos too!!

It helps to have a radio that fits your hand well enough to drive one handed

I can barely stand and drive at the same time. Never mind a camera.

[LuckyDuc]

The Eagle Tree with GPS logs the number of satellites you have locked at each data sampling. If you get an unusually high speed, check the number of satellites for that sampling. I'd be willing to bet that it only had 3 or less satellites locked. I don't trust a speed reading unless I have 4 or more satellites locked.

See example below...

[ezhitz]

I agree with looking at 3-4 runs in the same day will give you a better idea. Heres one from a boat thats lucky to see 50 mph.I guess you can use a reading like that to fool somebody that didn't know better after all the gps said so LOL.