Are phone GPS chips accurate for speed

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R055

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Hey guys, I was looking to get a GPS speed unit to add to my dash till I found out how expensive they are. I have my phone with navionics, is the GPS speed displayed on it accurate? Did most people use their phones when they wrote "my max speed xxmph verified by gps"?
 

dozerII

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Hey guys, I was looking to get a GPS speed unit to add to my dash till I found out how expensive they are. I have my phone with navionics, is the GPS speed displayed on it accurate? Did most people use their phones when they wrote "my max speed xxmph verified by gps"?



Yes they are very accurate, there are any number of free speedo apps available for your smart phone.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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my phone GPS speed matches my dash GPS speed if that is what you are asking.
 

oldjeep

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There are plenty of inexpensive Gps speedometers out there, but the phone works fine too.
 

roffey

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Set your cruise in your vehicle and compare to the phone app

The speedometer in your car is not accurate, better than your boat but still not accurate. Tire size, ware and other factors will play a large factor. IMHO, use the GPS on your phone.

How fast you go on the water is measured by the smile on your face, smile-o-meter.
 

David Young

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GPS is GPS. Phone, speedometer, Fishfinder, etc. They will all be accurate :)
 

southkogs

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I would say my Garmin GPS is more accurate, but the Navionics on my iPhone is a pretty close second. Both are more accurate than the speedometer is (both car and boat).
 

roffey

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I would say my Garmin GPS is more accurate, but the Navionics on my iPhone is a pretty close second. Both are more accurate than the speedometer is (both car and boat).

I suspect your Garmin will be more accurate but the phone GPS will not be wrong. The speed on my boat is say 35.4 MPH and the Garmin will be 35.44?
 

southkogs

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I suspect your Garmin will be more accurate but the phone GPS will not be wrong. The speed on my boat is say 35.4 MPH and the Garmin will be 35.44?
LOL ... I'm not even being that accurate. I forget the numbers, but I think the Garmin has a better satellite connection and receives more updated signals than the iPhone does. I would say you might even be right on how different they are, but I'm sure it's not much more than 1 or 1.5 MPH off. I know the Garmin can get me closer to a precise LAT/LONG spot than the iPhone ... but again: feet, not miles.

So, "yup," you're right.
 

SkaterRace

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I would say my Garmin GPS is more accurate, but the Navionics on my iPhone is a pretty close second. Both are more accurate than the speedometer is (both car and boat).
In the navonics app, where the heck is the speed? I have been using it for a bit and never came across it.
 

bruceb58

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The GPS receiver itself is only calculating location...it doesn't calculate speed. The software in the device uses the location values over time to determine the speed so depends on how accurate the device is with its time base and how often it does the calculation. Close enough for boating though.
 

frantically relaxing

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Any GPS SHOULD be accurate, but so should tire gauges. Pick up any 3 gauges and check your tires. Chances are you'll get 3 different readings ;)
 

dingbat

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They advise 1-3% accuracy for the latest smart phones but they are now where as precise as my chart plotter readings.
 

roffey

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Any GPS SHOULD be accurate, but so should tire gauges. Pick up any 3 gauges and check your tires. Chances are you'll get 3 different readings ;)

I'm to go out on a limb here. I disagree, a tire gauge is mechanical and GPS is electronic... and if you disagree with me..... I'll take your work on it, LOL.

I am a IT person, nothing to do with mechanical or GPS....
 

roffey

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This weekend I am going to go out on the water and will bring two phones, a blackberry, IPhone 6 and a tire gauge. I will do extensive study's on the water and bring back my finding. These are just some of the things I do for you Iboat people.

.. to let you know ahead of time I am sure the tire gauge will not be much use on the water but I want to be fair and do a complete study.
 

R055

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Thanks guys, I'm going to get a windshield mount and mount my phone with navionics so I can see more accurate speed and one of the lakes I go to have lots of twists and turns so I'll also use it for navigation while I'm still new to the lake.

In other news I fixed my boat speedo, the tube at the top of the lower unit on outdrive was disconnected.
 

R055

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In the navonics app, where the heck is the speed? I have been using it for a bit and never came across it.

I've always had it since I got the app
 

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