An In-Depth Swimming Comparison between the Garmin FR910XT and the FINIS Swimsense

Without question, the most common request I get these days related to the FR910XT has been about the swimming pieces. Unfortunately, it wasn’t until just recently that I’ve been able to fully dive into this area.  While the FR910XT’s swimming function has been functional in the pool since nearly day 1 for my test unit, the Garmin Connect website was only recently updated for swimming. Thus it hasn’t been until just the last 10 days that I’ve been able to finally see all the data I’ve been collecting, beyond what’s been on the watch.

But, the FR910XT isn’t the only game in town.  And certainly not the first.  The other major competitor in this space is the FINIS Swimsense by Sportsense.  This unit costs less half as much as the FR910XT, though is strictly pool bound.  Why not the Pool-mate Pro?  Well, given it’s roughly the same price as the Swimsense, but lacks some of the data options, I generally don’t recommend it anymore.  See my full explanation at the very end.

As a result of the FR910XT adding in pool swimming functionality, I’ve been flooded with requests to put up a review of how the two compete head to head.  And, until Garmin Connect was updated – I was hesitant to do so, since I wouldn’t have had the whole story.  But now that it’s updated, I’m ready to pull off the covers and go deep on the units capabilities, and how it compares with the Swimsense.

Because the Swimsense unit doesn’t do openwater (lacks a GPS), I’ve split up all of the sections into being either in the pool, or outdoors – so we can compare apples to apples.  With that, let’s start in the pool.

In the pool: Data and Functionality

Both the FR910XT and the Swimsense units use internal accelerometers to determine everything from the strokes you’ve taken to the swimming stroke type (i.e. freestyle, back, etc…), to when you turn around and start a new lap.

In fact, both units easily work whether you do flip turns or open (no flip) turns.  There’s no need to configure it. I could (and have for testing purposes) done a different type of turn every length and it’ll correctly record that as a new length.  The key trigger point for these units is really the change in direction – since that’s primarily what an accelerometer is measuring, directional change and speed.  In many ways, it’s no different than the accelerometer inside your phone that allows you to play certain games (or rotates the screen).

(The Swimsense watch…and me, above)

When it comes to the pool, these units are both incredibly accurate.  I’ve been using the Swimsense unit now for a year as my day to day swim watch.  And in the case of the FR910XT, I’ve been using it since early October as a swim watch as well.  In almost every case, both watches recorded the exact same distance on the unit.

The very few cases where they weren’t correct, where usually caused by my own stupidity (stopping midway down a lane), or accidentally forgetting to hit stop/pause at the end of a lap.  So long as you don’t do the YMCA song within each set – these units have no problems tracking your swims.  Note that I can really only speak to the freestyle stroke, since my ability to do any other strokes would likely injury myself or others.

Pool Length Configuration:

Both units support changing the size of the pool.  This is particularly useful not only for switching between your standard 25y and 50m pools, but perhaps more importantly, all the whacky hotel pool lengths.  As a frequent traveler, I’m always trying to use the device in pools that have bizarre lengths.  Take for example, this pool in Amman, Jordan.  Yes, the sky sparkles.  No, I don’t know why.

In the case of the Swimsense unit, you can do this both on the unit, as well as in software beforehand.  The Swimsense unit supports pools with a single length of 15 yards/meters to 50 yards/meters:

In the case of the FR910XT, the pool size is configured on the unit itself.  You can configure a minimum pool size of 22 yards/meters, and a maximum pool size of 100 yards/meters.  It has quicksets for 25 yards/meters, and 50 yards/meters, plus two additional options for the custom yards/custom meters:

Paused Time:

Both watches understand paused time.  This is a fairly important concept in swimming, where you may spend time at the wall that you don’t want to be included within your actual splits.  In the case of the Swimsense watch, it’ll invert the colors – and then count paused time for you.  This is also recorded separately later.

And in the case of the FR910XT, it just keeps the display like normal, but later on it accounts for it within your workout.  If you want to see the time (like the Swimsense), you’ll just hit lap instead of hitting stop/start.  Below is how the 910XT shows paused time in Garmin Connect if you press stop/start at the start/end of each set (along with reset lap).

Auto Pause/Auto Intervals:

The Swimsense unit includes a pretty cool feature which enables it to automatically pause the unit once you stop at the wall – without you ever touching anything on the watch.  It even accounts for the time between when you stopped moving and when it triggers the pause (usually about 2 seconds).

Having used this now for a month – it works really well, and is really cool.  In short, if you go out and swim 100 yards in 1:20, then stop at the wall for 30 seconds, it’ll automatically record 100yds at 1:20, and then show 30 seconds of paused time.  All without any button presses.

Today, the FR910XT has no such capabilities.

Alerts:

The FR910XT can trigger vibration/audible/display alerts based on both distance and time.  This allows you to automatically alert you, for example, every 500 yards.  Or every 10 minutes.  You can configure these alerts within the configuration option within the swimming mode.  Note that you can specify different alerts for swimming than for running/cycling.

Intervals (workouts):

Just to cover all the bases here – neither watch supports any concept of workout creation or following of workouts at this time.  Though, I strongly suspect that both watches will have it sooner or later.

On Device Viewable History:

Both watches support viewing history on the units themselves (separate from the mounds of data that both devices download to your computer).  You can drill down into per set and per length history.  The FR910XT also has a bit more in this area as far as per length/per set metrics that are additionally displayed:

In the pool: Display Configurability

Swim watches of the past have a fairly static configuration, mostly showing you total distance and time – and occasionally strokes and lap count are tossed in.  But if you didn’t like that configuration, you’re out of luck.  But fear not – both the FR910XT and the Swimsense are configurable.  Yup – you heard that right.  As of today, the Swimsense watch is now indeed fully customizable (just enable beta mode when it shows up later tonight).

Let’s start off with the Swimsense.  In this case, you use the Swimsense Bridge software configuration tool to configure the screens.  The device supports up to five different configuration screens, each with up to three pages of information on each.

Within the tool you’ll select the configuration template for that page you want on the left side side, and then populate it with data from the fields on the right side.  Note that on the right side there are two sets of fields – ones for total workout, and ones for ‘interval metrics’.  Interval metrics merely means lap/set metrics.

On the unit itself, the interval metrics are shown with an underline under the metric’s name, so you know that it’s a lap/interval/set metric.  Cool stuff.  Overall, I love the software configuration tool.  While you can’t configure the display pages on the unit itself, since there are so many pages, you have plenty of options ahead of time to work with.  Plus, the software configuration tool is far faster than doing it on the unit itself, like the FR910XT.

Switching to the FR910XT, you’ve got a slew of different configuration pages.  All of these pages are configured within the Data Fields option under swimming.  Different pages are configured for indoor and outdoor swimming.  If you’re familiar with changing data pages on the FR310XT for running or cycling, it’s identical for swimming.

Within the FR910XT you can display up to four data fields per page, and up to four data pages.

The total fields available to select are as follows, starting with the FR910XT for indoor fields:

Then the FR910XT for openwater data fields:

And now the FINIS Swimsense data fields:

In the case of the FR910XT there’s a bit more flexibility in terms of data fields, but by the same token – both the Swimsense and the FR910XT can have new data fields added with firmware/software updates pretty easily down the road.  So I could easily see this changing.  As far as the method of data field changes go – I really found the software configuration tool easy to use on the Swimsense (and it just hit beta today).  But I also like the fact that I can change fields on the fly, such as with the FR910XT.  In my ideal world, both units would allow data field changes online and on the unit.  I think that in the FR910XT’s case, having data fields (across all sports, not just swimming) be configurable online with Garmin Connect would have the added bonus of being able to potentially share data fields (just like Timex with their Timex Global Trainer and Timex Run Trainer) – and serve as a backup.

In either case, both watches offer tons of flexibility here.  You really can’t go wrong.

In the pool: Device Size, Screen Display/Backlight and Battery Life

This is probably the one area that the units differ the most.  The differences primarily stem from hardware design decisions made to support each units primary purpose.  For example, in the case of the Swimsense watch, it doesn’t have to worry about the extra size and battery requirements of a GPS that the FR910XT does for non-pool activities.

Device Size:

Without question, the Swimsense is smaller than the FR910XT – and by a fair bit.  In addition to being smaller from a width/length standpoint, the unit is also slimmer from a depth perspective:

Now, the Swimsense isn’t as small as the PoolMate Pro (which I’m not featuring in this comparison, see later explanation why).  So it’s slightly larger than a regular wrist watch from a width perspective, but the depth and height is about the same.

Screen Display & Backlight:

This is probably the single biggest gap between the two devices – with the FR910XT winning by a significant margin.  The FR910XT’s backlit screen is absolutely brilliant, sharp and easy to read from quite far away.

It’s funny though, up until I got the FR910XT, I used my Swimsense for everything – and got used to the display.  But since using the FR910XT, the display quality is just so different.  With the Swimsense unit you’ll learn to twist your wrist to just the perfect angle to see the numbers on a flip/open turn (it’s not hard, again, you get used to it easily) – but on the FR910XT one of the elderly water aerobics ladies a few lanes over can probably read the numbers.

Also of note is that the Swimsense unit does not have a backlight.  It does however have a nice function where it inverts the coloring on the display in paused mode.  This means that the white spaces become black, and the black spaces white – which makes it easy to remember its in paused mode.  Above is actually an example of paused mode.

Battery life:

The two units both have significant battery life, especially when it comes to average swim times.  The Swimsense unit received an update early 2011 that pushed the battery life to over 150 hours in standby – a significant change (12 hours active swimming).  This is nice because I don’t even have to turn the thing off, I just leave it on in my swim bag or lying around, and then when I sync with my computer I simply let it charge fully.

On the FR910XT side, the unit with GPS enabled (outdoors) has a life of 20 hours.  But indoors with GPS off you get significantly more.  While there isn’t any different official battery recommendations for indoors with GPS off, my testing has shown that you can get about 54-56 hours of life, though that’s without the accelerometer moving  so that may impact that number.  I just haven’t swam for 55 hours to validate that.  Either way, pretty impressive stuff.  Of course, you’ll more than likely want to download well before then (though, the unit has plenty of memory to keep it all too).

Openwater: FR910XT Data, Functionality and Accuracy

The Swimsense unit lacks a GPS receiver in it, and thus is incapable of openwater swims (since all of its data depends on its internal accelerometer).  However, the FR910XT follows in the FR310XT’s footsteps and provides openwater swim data.

However, like the FR310XT, the data isn’t quite 100% accurate.  It’s something of a best effort.  You may remember when the openwater swim mode was added to the FR310XT back two years ago.  During my testing at the time I found that it helped, but wasn’t super accurate.  It also didn’t fix the mapping issues to present a pretty map.

With the FR910XT however, things have been improved a bit – and I’ve found that the unit is within about 10-15% of the ‘real’ distance.

[Updated: In my original post I had a map that hadn’t changed much, however, it turns out that my FR910XT back in October when I did the openwater tests didn’t have all of the smoothing in it yet – logical since it was still in beta, thus, here’s an updated swim from November with correct/updated mapping algorithm in it.]

As you can see, the mapping has been significantly changed in the FR910XT, compared to the older crazy-whacky maps of the FR310XT on your wrist.  Looking for me to include more maps with the newer firmware

Due to DC being an area without any legal openwater swimming (yes, it’s a pain), I was only able to get some openwater time in during a recent trip to Chicago.  So, my experiences are limited to a handful of openwater swims there.  On the bright side, an upcoming trip to the southern hemisphere in two weeks will afford me significant openwater swimming time (daily basis) – so I’m looking forward to really sorting out the exact outdoor accuracy levels.

In the meantime, here’s the skinny on outdoor swims.

While swimming in openwater with the FR910XT you’ll receive distance and stroke information in real-time.  This means as you swim you’ll see the distance increment on the unit.  Same goes for pace information – such as rate per 100/yards.

This is actually pretty darn cool – especially if you’ve got water clear enough where you can make out this information (no, the Potomac is not clear enough).  But Chicago was.  You’ll also get strokes per minute.  In fact, here’s the full chart of all the fun things you’ll get.

So how’d I measure accuracy?  Well, I had three watches on (note, the importance of the word ‘had’).  The first was the FR910XT itself, it was on my left wrist.  Then I had the FR310XT on my right wrist.  And lastly, I had another FR310XT in my swim cap.  I’ve long since proven that the swimcap method can produce near perfect accuracy results if you place it correctly.

With everything set, I set out.  I ended up just following the buoys – since that’s the easiest.  Simple out and backs.

When I returned from my first out and back, here’s what I gathered:

In this case, .52 miles equals 915 yards (unit from my head).  So it was 1077 yards versus 915 yards – or about 85% accurate. So, to recap:

FR910XT (left wrist): 1077 yards
FR310XT (swim cap reference): 915 yards

Now, as I was heading back into the water on my second set a bad thing happened.  Said bad thing resulted in my reference FR310XT being lost to Lake Michigan.  Thus, I don’t have the pretty maps from it.  No, it was not the quick release’s fault, but rather just a simple stumble on my part before I had the unit secured.

In the next test, I did another set – a loop of sorts around the beach area.  In this scenario, I was curious how different the two units would be.  I found that the FR910XT resulted in a 1023 yard swim, whereas the FR310XT on my other wrist came in at 704 yards.  I don’t know the exact distance, but I’d guess it closer to the FR910XT number, in my first test, the units remained on while I stopped midway to take a few photos, whereas in the second test the swim was nonstop.  Plus, if I swam 14 minutes and only went 704 yards, my swimming would have suffered far more than I thought – especially with a wetsuit!

So where does this leave us with openwater swimming?  Well, the data has been significantly improved – since it now contains stroke information.  Also, the 910XT contains a fair bit more smoothing via algorithms to make the maps look more realistic (though not precise).

However of more interest than mapping is that the FR910XT will provide some very interesting stroke numbers outdoors.  In particular, I’d love to see strokes per minute over the course of a long distance swim (i.e. 2.4 miles+).  It would be really fascinating to know if/how ones stroke rate changes over the course of such a swim.

Again, I should be able to really populate quite a bit of data into this in a couple weeks once in some openwater swim-friendly weather.

Openwater: FR910XT Device Size, Wetsuit Removal and Battery life

For those of you that have swam with the FR310XT in the past on your wrist you know that it can be a bit of a pain in the butt to remove your wetsuit due to the design of the unit.  Well, the FR910XT fixes that.  They specifically made the unit’s design such that it hugs your wrist better and attempts to be as slim as possible so that your wetsuit will pull right off over it.

So I decided to put that to the test.  I was curious to see if it would actually pull right off – in one shot.  So I asked The Girl to video tape the thing (which I only did one take of) – and I ran back out into the water and swam a bit and then came towards the beach – just like a real triathlon.  None of this staged stuff here on this site.

Here’s the results – video style.  Note, the unit is/was on my left wrist – or the right side from your point of view.

FR910XT Wetsuit Removal.

Indeed, it does pretty much exactly what they say. It briefly hung for a split second, but then went right over without issue with a quick tug.

Finally, battery life.  Since the FR910XT will use the GPS while outdoors, its limited to the GPS battery life restrictions which peg it at about 20 hours.  So plenty for inclusion in a full Ironman, or, if you’re a openwater long distance swimmer – enough for most English Channel swim crossings.

Websites: Data display and functionality comparison

Both Garmin and Sportsense (the company behind the Swimsense) have websites that allow you to view and analyze your data.  Sportsense has had theirs since the beginning of time, whereas Garmin just recently updated Garmin Connect about 8 days ago to provide the additional FR910XT swim metrics.

Let’s briefly dive into these at a high level, starting with Garmin Connect.

Garmin Connect:

Garmin Connect has a few new tricks up its sleeve to show off the swimming functionality.  Let’s first start at the overall workout view, and then dive into the notable sections.  Once you upload your workout, this is what you’ll see in the activity details pane:

The first thing regular Garmin Connect users will notice is the swim graph section (purple – an interesting choice of colors considering Kansas State not too far away…).  This sliding chart moves left and right to show you each length, and then the interval that they are part of above it.

Below you can see the paused time in between the two sets:

Note that the different strokes have different colors:

Moving to the left side of the pane, you’ll see all the summary information for your swim.  Note the efficiency, SWOLF  and stroke information – as well as the fact that pace is now shown in the standard time/100 yards.

And below that, we’ve got a vertical interval panel:

However if you select the interval button, you can get more details.  You can also click to expand any given interval (set) and see the individual lengths:

(Note: The two sets with 25yds in them were purely my fault – I had stopped midlane as my lane mate had something to convey.)

Next, we’ve got the three main charts showing timing, strokes and efficiency:

And that’s pretty much the wrap-up of the FR910XT online portions.  I’d expect (in fact, I know) that others like Training Peaks, Sport Tracks and more are hard at work getting swimming data support for the FR910XT – so expect to see some pretty cool analysis down the line.

Swimsense Site:

When you first login to the Swimsense site, you’re greeted with an overview of your swim, a bunch of charts, and the interval timeline:

Let’s start at the top, which actually controls everything down below.  This is the slider, and works in much the same way as the Garmin slider, you slide left and right to dig into your lengths/intervals and total swim.

As you click different sets, the detailed information changes to reflect that set:

You can see the paused time in between the sets, in the timeline view:

Also note that I can click on any given length, and see the detailed information about that specific length:

Like Garmin Connect, the Swimsense site will automatically change the color of the different strokes within the timeline view based on the stroke type:

One area that the Swimsense site has that Garmin Connect doesn’t is automatic transfers to other applications.  For example, as soon as I upload my swim with the Swimsense unit to their site, it automatically gets transferred to Training Peaks (the site).  I don’t have to do any more to have my data show up there.  In fact, I don’t even need to ever login to the Swimsense site after setting that up initially.  And Sport Tracks also supports it today as well.

Software Summary:

Both the Swimsense site and Garmin Connect contain social media sharing features, as well as the ability to export out the data as CSV files.  Both also have calendar options and activity lists, so you can easily sort and see your workouts en mass as well.  So they’re pretty equal here.  Swimsense is a bit ahead of the curve when it comes to other companies being able to process their data, but I expect that other companies will quickly catch up.

And overall, both units contain pretty much the same features when it comes to online analysis – they just display it a bit differently.  Both units also record per length data – which is key for later analysis.

Side by side comparison chart:

I’ve gone ahead and put together a detailed comparison chart of all the features I could think of between the two devices.  Then I decided to add in the FR310XT just for a quick comparisons sake:

Note: You can click to expand the chart.

Summary:

So which one to choose?

Well, honestly it primarily comes down to cost – and which devices you already have.  If you already have a Garmin device and don’t intend on purchasing another one, then the Swimsense is an awesome addition to the stable to gather your swim metrics.  It easily does virtually everything the FR910XT does indoors.  And does so for half the price.

But if you’re looking to upgrade to the FR910XT for other sports, or have the cash to spend – then you certainly can’t go wrong with the FR910XT.  Additionally, if you’re a long distance swimmer – it may end up being a must have.  It’s got both indoor and openwater tracking, so you can switch easily.  And the display is brilliant.

I expect to see both companies battling it out on the software front.  There’s a lot of potential for both devices, starting with the ability to create/customize workouts – and then going from there. Swimsense’s recent addition (today!) of the data page display capability captures that point precisely.  And their recent addition of the interval mode last month only further proves that.  But Garmin is looking at their list of potential feature adds as well, so expect lots of back and forth here.

In the end – you can’t go wrong with either device.  They’re both very accurate in the pool and capture the same level of data (per length with per length stroke information).

As always, if you have any questions – feel free to drop them below.  If you have non-swimming questions on the FR910XT, your best to post them on the In Depth 910XT Review post. Thanks for reading!

Final Note: Why I didn’t include the Pool-Mate Pro:

I wanted to preemptively answer this question.  The Pool-Mate Pro is priced at approximately the same price as the Swimsense.  But in my opinion, it doesn’t deliver the same data, nor does it do it in a competitive way – especially with the recent Swimsense updates this fall.  I’ve always believed that I don’t write large chunks of text on products that just don’t meet the bar – it simply takes away from time I can spend on other posts.  And in this case, the unit doesn’t do per-length data, nor is the display customizable.  While the unit does have the ability to download data, you can’t really get that data into any other sites out there.  I do however like the fact that the battery will last a year – and its smaller, but I counter that with the frustrating user interface (I know, some of you love it…for me it frustrates me).  But, that said, you can read what I wrote on it last winter in my in-depth review – and decide if it makes sense for you.  Or read my Swimsense vs Pool-Mate Pro post.  Keep in mind quite a bit has been added to the Swimsense since then.  Enjoy!

Software Developer Final Note: Since I’ve received a few requests for the Garmin FR910XT files, I’ve gone ahead and placed four example files (two indoor swimming, two outdoor swimming) in a .zip file you can download.  I’ve included both .FIT and TCX files, and if you want, you can upload either to Garmin Connect to play around with the data (or to develop apps against).  Note however that the outdoor swimming ones were done with much earlier beta firmware, and may no longer be accurate of the final data structures and may have some earlier beta bugs.  The next opportunity to swim outdoors for me will be later this month when visiting the southern hemisphere.  I’ll have plenty of FR910XT swim time then.  Speaking of which…that reminds me, I need to order a new wetsuit, I managed to finally rip a massive hole in my older one, in Chicago. Rest in peace wetsuit, you were good!

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