Garmin Max Speed

When we do a downwind, the first thing we do at the end is look and see what our max speeds were trying to top the others. I ran a 301 and a 305 at one time for a few trips in my boat and had different max speeds each time; the 301 always read a mile or two faster for the max. I know the 301 was always more responsive so I just figure that was the difference. My real question now though is I'm getting max speeds sometimes that are faster than my partners (and I) believe. Yesterday, on a wide open body of water with 6 foot wind driven waves I ended up with a max on the unit read 14.2, and Garmin Connect shows a max of 23.4 but the max peek in the graph is 16. Of course I want to take credit for the 23.4 but only if it is real. Thanks

connect.garmin.com/activity/230049842

Garmin connect smooths the data, but it does keep the logged max speeds etc.
It does this to save storage space on the server.
Your max speed simply got smoothed out on the graph.

Download 'Training centre' and view your file, you will find that if you turn of any smoothing and look at the data and the graphs, your max speed will be obvious.

Garmin connect is simply too crude with it's information to do any serious data analysis.
It's more for letting your friends see what you are doing.

Your two devices may have different software releases and may integrate data differently or they may have been locked onto differing satellites with differing degrees of accuracy.

Simply by having one second updates enabled on one device and not the other will create quite large differences.

Even starting one a split second after the other will have each device logging data for a differing time parcel which will always be a little different.

Great tools, but you need to understand the limitations of them.

These Garmin wrist devices do tend to spit out some funny numbers at times. Before I got mine I used to use a larger Garmin GPSmap76CSx which I have found not to give any strange readings and seems to be a lot more accurate. When comparing with my friends results on shore my 76CSx will be on 0kph standing still and my friends 310xt would be jumping from 0kph to 5kph and back and forward. This leads me to believe the wrist units should not be trusted to be bang on accurate at all times. Even when we were paddling the speeds recorded were about 2kph different. Might have been just his unit, mine seems to be pretty good other than the odd strange reading.
Sometimes I used to fit my 310xt to my ski and push start before hitting the water thinking that because the threshold for recording a reading would mean that it wouldn't start logging until I was paddling. Then on downloading I would find I started paddling at 78kph for a second or two, so that is obviously wrong, now I only pust start once on the water.
There were some wild numbers coming off a Garmin some months back with the paddlers claiming 68kph on waves, analysis of the track showed these high speeds were attained in turns and paddling into the wind even and proven to be bogus figures.
Don't believe everything you see on your data, if it seems to be too good to be true, well just be aware it might not be.

The early firmware for the XT was nowhere near as accurate for speed.
The later releases were much better.
From when they introduced 1 sec updates onwards it is quite accurate.

I find there is still some variation of altitude if I compare it to my Edge 500 on the bike.
The Edge has the benefit of a wheel sensor for help with speed and distance as well as a barometer built in.
It is far far more accurate with it's elevation readings.

This is mostly due the wheel sensor as it keeps track better when reception is a little broken up.
Without the wheel sensor it is roughly the same as the XT.

Whenever you see those wild readings as you start off, it's because you didn't give it a chance to get a proper satellite lock before you set off moving.

A full bucket can loose it's lock sometimes (not often)and it will always loose it's lock with the ski being upside down if it mounted on the foot straps.

Couple of things in reply to RAB, the elevation is always way out on my 310xt, all over the place compared to my 76CSx, todays one hour paddle on flat water shows a 13m variance with me being between 5m and 18m.
As for not allowing it to get a proper satellite lock before setting off, thats bunkin, first thing I do after placing ski on ground is turn on my Garmin, then fit water bladder, check Garmin and attach to its mount at my feet, fit rudder arm cover, put my paddle together, pull on my PFD, high viz vest, hat, glasses, gloves, move car and park, walk back to ski, do a few more warm ups, pick up ski and walk 20-30 metres to water, put on leg rope, connect water tube to vest, place plastic bag on seat, jump on and paddle away. Surely thats plenty of time for the Garmin to get a satellite fix before setting off.

Do you use elevation correction when you use Garmin connect?
Or do you analyse the data with something else?
What firmware version?
Do you have 1 second recording enabled?

Yes I use elevation correction, firmware version 4.20.0.0 and I just checked and it was set on smart recording, so we will try it on 1 second recording to see if that improves things. It was not something I was aware off so thank you for bringing it to my attention.

With 1 second recording enabled the elevation ranged from -32m to 47m thats a range of 79m. So it was worse than yesterday using smart recording.

But elevation is not really a concern of mine, I wouldn't worry if it did not show it at all, but interesting to point out that these devices cannot be relied upon to be accurate at all times.

Can you compare it to a paddling buddies identical one?
I don't see anywhere near that sort of variation.

I just checked back through my last 6 paddles.
All the files have elevation envelopes of around 8 to 10m.

I would contact Garmin if I were you.....


Or maybe do a total reset first and see if it is any better....

Its had several resets over the past year, looking back the elevation has always been inaccurate. Just noticed there is a new version of the software available, 4.50, just installing it now. Most of my paddling is solo. Like I said earlier, I've seen other Garmin 310xt's with strange numbers and readings either on the unit or via Garmin Connect. My unit is a useful training tool, but I'm not surprised by the odd out there reading.

Kayaker Greg wrote: ... the elevation ranged from -32m to 47m thats a range of 79m. ....

Perhaps you were on some REALLY BIG waves !

I looked at the data on the garmin training center and it showed one max speed of 30mph, a couple in the 20s as well. I did go in a couple times that day, but the max speeds did not correlate with the tip as near as I could tell. I expected to see a 0 from the tip and then a big max after that like I might get after going under a bridge. Not the case. Do others get maxs like these? My vertical is pretty wide as well. On Garmin Connect a friend of mine said "it shows the 3 feet drop to the lake and back off the lake but no elevation on the lake. In the training center it shows most of the elevation within 10 meters but highs and low spikes put the range closet to 25 meters.

Data from recent paddle Swan River above on Strava, conditions ambiently perfect for flat water paddle. Being the god of paddling I am, the almost 20 kmh top speed with heart rate at about 63% max was nothing surprising (haha) even after paddling through Claremont jetty, however despite my Garmin obviously being hijacked by something (can't recall seeing anything else out there but whatever) how can a course be plotted by GPS (Garmin Edge 510) like this?

I left the beach with a mate and headed directly for a distant spit effectively travelling same course as on return journey plotted there. There was none else out I can recall as mentioned. Even so, why would my GPS course not leap at some point from whatever hijacked my device, back in a direct line back to my course?

This (a course change as direct straight line back to my device ) has happened previously where a speedboat accompanying rowers has grabbed by signal and shot off on its own course at, then my signal returning to me in a straight line - ping, sorry, back to John now. I understand that. But on the above as much as i would have loved to, I was not going much over 10kmh.

Second question: how risky would it be using a Garmin 510 Edge (IP07) in my ski? I have used it previously, it has been immersed in pocket of PFD no big deal, but what about exposed in boat, human rotisserie on a big day?

I have a Garmin E Trex which is a cool unit because it shows all of the data on a single screen. But, I have learned that max speed is not the number to pay attention to. I have seen 9.0 mph paddling on flat water and I know that I am not the kind of paddler that can do that. What happens is the max speed number can get "spiked" by several really good paddle strokes. What I look at now is the average speed number. You have to hold an increase in speed for quite a distance for the average to move up. Also, really quick changes in direction can skew the max number.