DC Rainmaker

FINIS AquaPulse In Depth Review

Today FINIS announced their latest product, the AquaPulse underwater audible heart rate monitor.  Unlike most sport heart rate monitors however, this one doesn’t measure your heart rate using a standard chest strap, but instead does so at your ear…conveniently placed right where your goggle strap would be.  The unit uses infrared light to measure capillaries pulsing inside your earlobe.  Think of it like a little x-ray for your ear.  From there the unit then reads back the heart rate reading to you audibly, via bone conduction audio.

Those familiar with many of the underwater MP3 players on the market may be familiar with such placement.  The AquaPulse works the same way, by conveying audio through your jawbone and into your inner ear all without any pesky ear buds.  It’s just as if someone placed a speaker right next to your head.

But before we get to the details, let’s start at the very beginning (just like the Sound of Music song).  I received the AquaPulse back about a month ago to play around with, and have both spent some time in the pool with it, as well as on the phone with the folks from FINIS getting all the details on both current – as well as upcoming product.

An interesting backstory:

Some of the more historically minded folks may know/realize/remember that the AquaPulse was actually announced almost two years ago.  In fact, it was my recent Slowtwitch post noting it’s apparent death before arrival that triggered the entire reason I got this post.

It turned out that after a good long conversation with the CEO of FINIS – John Mix, that in reality they had simply started back from scratch.  Some two years ago during final testing in pre-production units, they were finding about a 5% error rate where the HR data would disappear.   Instead of shipping the product the company decided to delay release and engineer some more.  Unfortunately, in the process they lost a key (or perhaps more accurately, the key) engineer working on the project – ultimately resulting in the entire project having to be started back from scratch again. A process that would take nearly two more years.

Why do I mention this?  Well, for two reasons.  First, it shows that unlike some companies in the sports technology world who may ship a product with a 5% error rate, FINIS wasn’t willing to.  And secondly, because I thought was interesting.  Most companies wouldn’t have been ‘man enough’ to admit that they had to go back to the drawing board to make it right.

With that, it’s time to unbox this puppy.


For those with the FINIS Swimsense unit – you’ll find the packaging remarkably similar.  To make that point, I present you the AquaPulse unit on the left, and the Swimsense unit on the right:

But let’s focus on the AquaPulse unit:

Once you crack open the box you’ll find the unit itself nestled in layers of carefully sculpted packing foam.

After removal of everything in the box you’ll have the following rather simplistic arrangement:

The AquaPulse itself is a rather bright yellow, which certainly makes it easy to find in your swim bag (unless you have a bright yellow swim bag).

You’ll notice on one end is the ear clip, which is what measures your heart rate:

And on the other side is a little rounded black cap that you can remove that contains the USB plug.  For those of you who remember the Nike+ GPS Sportwatch, you’ll note the similarities here with the case-less USB design.

This means that the unit itself stick straight into your computer, though a secondary extension cable is included if you don’t have a super-accessible USB port:

The USB port on the unit is used for charging, though there doesn’t appear to be any reason it can’t also update the firmware should that be required (though no software is included at the moment for that).

Finally, last but not least – we’ve got the simple paper manual.  Though, if you need it you can also just download the PDF file.

Like the Swimsense packaging, they do a good job at avoiding placing a lot of useless junk in the box – which is both good for the environment, and my post length.


Now that we’ve got it all unpacked, let’s get on with the basic configuration…which happens to be about all the configuration there is.  Just perhaps the simplest sports device you’ll ever use.

Once you turn it on you pretty much have only two configuration options:

1) Change Volume
2) Change Announcement Interval Rate (10s, 20s, 30s, 45s, 1m, 2m, 5m)

In addition, you have one button that will instantly read out the heart rate (as opposed to waiting for the interval to occur).

Changing the volume will increase the audible level from soft to fairly loud.  So loud in fact that in a semi-quiet room you can actually hear it pretty clearly, as I’ll demonstrate in a second with the below video.  Each time you increase/decrease the volume it’ll audibly say “Hello”, to allow you to hear what it sounds like.

To change the announcement rate you’ll hold the button and it’ll iterate through each setting, saying out loud “10 seconds” or “20 seconds”.  This means that every 10 seconds it’ll say your sampled heart rate average over the past three readings.

It’s a very simple configuration, though a bit of written descriptive text on the unit might help to make it clear which buttons are which.

I’ve gone ahead and created a very quick video clip which allows you to hear both the change in settings, but also the change in audio levels.

FINIS AquaPulse Audio Levels and Configuration

With everything ready to go, let’s head to the pool.

Use in Pool:

In order to use the AquaPulse you’ll simply clip it to the side of your goggles.  No need to undo any goggle straps though, this easily clips on just like those ever-stylish cell phone belt cases:

Once that’s set you’ll go ahead and turn it on by holding down the button with the dot on it.  It’ll take just a few seconds before saying “Hello!”.  At which point, you’re (almost) ready to rumble!

The last item to do is simply to attach the ear clip to your earlobe.  This just opens up and clips right onto the bottom of your earlobe (the part where earrings would go):

When it’s all complete – it’ll look just like the below…except likely not as goofy as me trying to take photos of myself underwater using large bulky underwater camera gear (you have no idea how many pics it took to get this so-so photo):

With that, you’ll simply start swimming.  Though even before you start it’ll likely be telling you your heart rate.  The unit doesn’t have to be below water to tell you heart rate.  In fact, I actually used it on a few indoor trainer (bike) rides just to compare heart rate values with a HR strap.

I’ve found that I prefer a setting of every 20-seconds (20s), simply because this means that for me I’ll get it roughly once per length right before/after the start of a turn if doing harder efforts.  Though I could see where 10s mode might be more useful (which you can change it to).

When it announces your heart rate it’s simply taking the average of the last three readings.  Meaning, if you had selected two-minute mode, it would simply tell you your heart rate over the last few seconds worth, rather than averaging it over the entire two minutes (which would be bad).

One item I found was that the direction in which you clipped the sensor onto your ear mattered.  In other words, if I clipped the sensor such that the thick side of the sensor was towards the inside I found it gave occasional inaccurate readings.  Whereas when I simply flipped it over – the readings were spot on 100% of the time.

I sent an e-mail over to the FINIS folks and got an answer back from their head of engineering on why exactly this is – which I thought was a pretty fair answer:

“The the unit may work slightly better for some people if the sensor is behind the earlobe. The padding is on the outside of the lobe and the sensor part (with wire) is behind the lobe, closer to the head. You may get slightly better readings in this position because there is less sunlight that could infiltrate the sensor, as it is being shaded by your ear. As you know, the sensor uses infrared so if sunlight seeps in, it could cause the sensor to misread. The same could also be true for bright fluorescent lights, but we actually found indoor lighting is less of a problem.”

Simply ensuring I have the padding side towards the outside is a trivial simple thing to do, and in my repeated swim sessions I found it worked flawlessly in this configuration.

Lastly, you may be wondering about that USB port used for charging.

No worries, it’s fully waterproofed – which means the little cap thing that you have on it can be safely removed without any concern for water leaking inside.  Once you’ve got the cap back on, it’ll look just like normal:

Oh, and finally – it’s not like a duck…and won’t float.  If you somehow manage to drop it, it will sink – albeit slowly – but just something to keep in mind.

Test/Accuracy Results:

As I noted before – the unit worked perfectly once I flipped the clip to the preferred direction.  I used it repeatedly in the pool over the course of a few weeks and found no issues at all.  I didn’t use it in an openwater setting (lake/ocean) merely because I didn’t have any openwater swims available to me at the time – but there’s absolutely nothing keeping you from using it in those settings.

Audio quality and loudness is more than adequate – despite even my most ‘intense’ swimming intervals (a fair bit of splashing) – I could still hear it.

Further, I also tested it in dryland scenarios – such as reading my resting heart rate (worked awesome!), to using it on an indoor trainer while doing my cycling workout.  Again, not a single problem there.  In tracked near perfectly with the Garmin and Polar Heart Rate monitoring devices I tested it out with – those that depend on a heart rate strap.

In cases where I wasn’t wearing goggles (dryland) I simply let it hang off my ear.  Not ideal, but then again with a little creativity you could easily retrofit a visor or the like, if you wanted to.

I asked about current deployment levels of the devices with other swimmers.  At the moment (pre-release) they have/had about 30-40 coaches and athletes using them on a regular basis.  They’ve also done some trials with swim teams as well.  One of the areas that teams found most interesting was in some of the younger kids (early teenage) where they hadn’t fully mastered perceived effort yet, it let them understand a bit better as to what a ‘hard’ effort might be.  In other words, if Johnny is doing a hard set at 170bpm, and then Phil comes back after doing his ‘hard’ set at 140bpm – Phil may need to reevaluate his definition of hard (of course perhaps he just has different HR zones).

The future:

In both my mind, as well as that of FINIS – the AquaPulse in it’s current iteration is merely the first step towards a more integrated swimming data solution.  Today the AquaPulse doesn’t record data, but there’s no question in the future it will.

They are currently looking at both integration with the FINIS Swimsense downloadable swimming watch, as well as integration with ANT+ devices (existing watches) for getting heart rate data to those.  Though there are some water barriers on the ANT+ front while underwater.  While the timelines aren’t entirely concrete – look for units with these capabilities start being available either just before or just after the Holiday season (the unit I describe here is available starting today).  FINIS was pretty clear to me that no matter the next product, they’ll offer some form of competitive upgrade path for current owners, as they don’t want to stall folks from picking it up today.

As part of that integration with downloadable data, they’d also be looking to take advantage of many of the features initially outlined by the Swimsense team around creating customized workouts (i.e. do 500y at XYZ Heart Rate), as well as team download capabilities.

Finally, I thought it was interesting that they’ve been approached by the Arizona Diamond Backs (MLB), Chelsea Football team and Denver Broncos (NFL) to put together an adapted version for use during dryland training that utilizes Bluetooth and an App of some sort to transmit data back to a centralized data point to monitor for irregularities.


This is one of the few sports technology products I’ve tested that’s both dead simple to use, as well as 100% reliable in what it does.  There were no ‘off days’ or ‘problematic days’ – it just worked every single time.  As a user, I really can’t ask for much more.


Pro’s and Con’s:


– Works reliably
– Super easy to use
– Doesn’t require a heart rate strap
– Can be adapted for other uses (i.e., resting heart rate)
– Easy to change both interval and volume
– Battery last more than enough for a swim (5-8hrs), easy to charge with USB


– Doesn’t record data
– Doesn’t float like a duck

If you’re looking for a way to measure heart rate in the pool – this is hands down the best way I’ve found yet.  While you could use a Polar HR monitor with the HR strap, I’ve found that personally it doesn’t work well for me as the strap slides down during faster sets (since it’s exposed, unlike if I were female and had a bathing suit covering it).  While the data doesn’t record like the Polar, I found it easier to focus on maintaining a given effort/heart rate than the Polar since it was like having a loudspeaker in the pool.  This means that midway through my sets when I’d find that I slipped a bit in effort, the unit was there happily reminding me…every 20 seconds.

Found this review useful?  Here’s the super easy no-pain way you can help support future reviews!  Read on…

The reviews generally take 20-40 hours to put together, so it’s a fair bit of work (and labor of love).  Also, as you probably noticed by looking below, I take time to answer all the questions posted in the comments – and there’s a lot of details in there as well.  So if you found this review helpful in your purchasing decision, you can support future reviews like this by using any of the Amazon links, such as the one to the left.  The AquaPulse retails for $149.

(FINIS provided a production sample of the AquaPulse to test with and the notation that I could keep it if I wanted.  Instead, at some point in the future that sample will be given away to y’all as part of a giveaway.  Maybe a big summer swimming clearance giveaway package!)