Hands-on: Waterfi’s Spotify Streaming Swimming Music Player


I’m a Spotify person. Sure, there are many audio services, but the one I listen to virtually the entire day (and at night with the kids) is Spotify.  Largely because it works anywhere I am in the world, without funky restrictions.  Regrettably though, when it comes to sports wearables, none of the majors offer options there.  Not Garmin (Deezer/iHeartRadio), nor Fitbit (Deezer/Pandora), nor Apple (just Apple), nor Polar (Google Play).  Sure, Samsung does on a handful of devices, but those devices aren’t terribly awesome at endurance sports.

Of course, the reasons most of these services can’t get Spotify is 100% on Spotify.  Not for lack of trying/desire by Garmin/Fitbit/etc…  All of which is somewhat beside the point in some ways, but it’s entirely the point for this post.

That’s because I just got back from the pool using Spotify while swimming laps.  But, before you get too distracted note that this Kickstarter project is only available for pre-order through Tuesday.  I personally don’t care whether or not you support the project, but since time is tight, I figured I’d mention that first in case you get distracted at lunch with those fries and don’t find this browser tab till late next week.  After Tuesday, their campaign closes.

The Tech:


Now Waterfi is hardly a new player to the water based wearable music scene.  In fact, I’ve tried their gizmos in the past – a long time ago.  That was the last time I did a round-up of pool swimming options, and ironically, the landscape has hardly changed since then.  For whatever reason, it’s a stagnant market.

Still, Waterfi’s got something unique here with their Swimcast product.  The small waterproof music player works by enabling your phone to stream content to it, exactly the way Google Chromecast works.  And by ‘exactly’, I mean, 100% precisely.  That’s because inside this little pod is actually a Google Chromecast Audio device.  Which doesn’t mean you need Android, it works just fine with iPhones too.

Now you may be wondering how that works when you bring in water.  But what Waterfi does is cache whatever it is that you’re steaming to it, so even as you go underwater pushing off the wall at the end of each length the audio doesn’t drop.

But first, let’s talk hardware basics.  You’ve got the Waterfi Swimcast pod seen below.  It’s got a waterproofed headphone jack (because Bluetooth doesn’t travel through water), which is all pretty much the same as most waterproof music players.  Ignore that this looks a bit rough (or that I got dirt from my picnic table on it).  Like most prototype devices, it’s simply 3D printed.  No different than 3D printed or early hand-made stuff I get from Garmin or any other big name company.


Next to it you’ve got a micro-USB charging port.  That too is waterproof, which has long been common on various devices out in the market for probably close to a decade.


And of course, then there’s the headphones themselves, which come with a bunch of tops:


And that’s it.  Now to understand a bit more on that Chromecast Audio inside it piece, they’ve got a nifty picture on their Kickstarter page that I’ve snippeted for here, it shows exactly what they’ve done on the inside:


With the hardware all covered, what happens next is that you’ll need to pair it up with the Google Home app.  Again, this can be on either Android or iOS.

2018-04-04 14.03.20 2018-04-04 14.03.30 2018-04-04 14.02.17

As part of this you’ll specify the WiFi network name, as well as give it a location.  In my case, I created a room called ‘Pool’, because…yeah.

2018-04-04 14.04.16 2018-04-04 14.03.46 2018-04-04 14.03.58

After you’ve got it paired up using Google Home, you can then use the ‘Cast’ option which sits in the upper right corner of most apps.  It’s the little square with a few radio signal looking things on it.  However, in Spotify, it shows up under the ‘Connect to a device’ menu’.  You can see below I changed from ‘Kitchen’ (at left) to ‘Pool Speaker’ (at right).

2018-04-04 15.45.04 2018-04-04 14.07.31

Note that the advantage to using Google Chromecast Audio and casting is that it’s actually not limited to Spotify.  Anything that plays music from your phone and has the ‘Cast’ option you can use, that includes:

– Pandora
– iHeartRadio
– YouTube/YouTube Music
– Apple Music
– Any audiobook service (i.e. Audible)
– Apps that make fart noises (for a concerto of farts)

Really, it doesn’t matter.  Just think of the Waterfi as kinda like a Bluetooth speaker (except not Bluetooth), it doesn’t care what you play to it, it just plays whatever it’s told via the Cast option, which is in the vast majority of entertainment apps out there today.

Finally, note that because the battery switch pieces haven’t been finalized yet, there wasn’t a way to power it off (or on).  It was always on, so they tossed in a small USB battery bank to keep it charged in my swim bag till I was ready to swim. After the swim, it simply ran out of juice eventually.  But again, that’ll all be sorted by launch – it’s just typical beta device stuff.


As a side note, I’ve got a lot of USB battery packs, and I’ve never seen one this thin before – about the size of a credit card, and only a few cards thick.  Pretty cool, found it on Amazon as well for only $11!

Ok, with all those basics covered, let’s head to the pool.

A Test Swim:

After a brief test in my living room (+ a microwave to simulate a faraday cage and lack of signal underwater), I headed across town to the pool to give it a shot.  I tossed my phone in my gym bag and left it pool-side. Certainly this was risky, given mid-afternoon in Amsterdam was a mix of 3-8 year olds….and….65-85 year old ladies doing pool aerobics, but…in the home of Stroopwafel I trust.

I got the Waterfi unit powered on and then enabled the Hotspot on my phone (an original Pixel phone), within a few seconds, the Swimcast player had found the hotspot and soon it was accessible in Spotify as a device I could stream to.

2018-04-04 15.45.39 2018-04-04 15.44.55

Again, I’m just using Spotify as an example because it’s what I use.  You can use anything you want.  I selected an appropriately random playlist – Beach Hits – and then slightly increased the volume to the midpoint.  Then I hit play and packed the phone away in my swim bag.


I also attached the Swimcast to my goggles near the back of my head.  It has these little hooks to latch onto your goggles and hold it tight.

2018-04-04 16.18.12

To give some context on distance and obstructions (since frankly, that’s the most important thing here), I left my bag in the furthest corner of the building I could.  A towel draped over it, where the arrow is.  There were lockers there, but alas I lacked whatever magical card you needed to use them. Though, they’d have been closer to the pool than my spot.


I then walked all the way to under where I took this photo to the showers to rinse off before entering the pool.  That’s about 50-75 meters away from my phone, obstructed by changing stalls and a few concrete pillars.  The audio never dropped once.

So then I simply jumped in the pool and began my laps (as best as possible given the cluster that the pool was – look, it’s my first week here in Amsterdam and I haven’t figured out the pool scene yet).

Almost instantly the audio dropped – within 5-7 seconds of starting.

Hmm, that’s odd (and non-ideal).

So I dorked around with the back of my head where the pod was, ensuring I tightened the headphone cable into the port, and then also positioning the pod slightly higher up on the back of my head.  The end resultant was this:


Then, I set out again.  And this time…it was perfect.

It never dropped, not once, during my laps swimming freestyle (which was all of them).  At both ends of the pool it was perfect…and any point in between.  When I reached the wall, I did flip turns as normal, and the audio kept on playing without issue.

Which made me wonder…how long would the audio play for when underwater?

So I held my breath and went under.  At precisely 20 seconds under, the audio cutout.

I then went above the water and let it reestablish connection and the audio continued playing.

Then I tried it again.

And again, 20 seconds after losing WiFi signal, it lost audio.

To me, that’s a reasonable timeframe.  About the only scenario I can think of in normal pool workouts where this would be a problem is those doing backstroke, because the pod would be below the water almost the entire time – thus preventing connectivity.

One item that’s worth pointing out is that the pod has no controls on it. So no stopping/starting/skipping/volume changes.  You can pair a small/cheap Bluetooth Smart remote to your phone though, and control that.  This remote could then simply sit inside a ZipLoc bag poolside (perhaps in a larger mesh bag with pool drill toys, or glued to a water bottle).  That would then allow control, assuming it could reach your phone.  Hardly perfect, but certainly an option.


Still, all in all – pretty darn cool.

I was pleasantly surprised how well the WiFi worked in the pool building.  I suppose that in many ways a pool is the perfect WiFi environment – there’s no walls or such in the middle of the pool sitting on the surface.  Thus WiFi carries well.  Of course, if you end up leaving your pool bag down deep in some basement locker room inside a swath of metal lockers, you’ll probably have a non-awesome experience.

In terms of theft of a swim bag depending on your pool facility design, you could also consider an older phone you have lying around as the dedicated pool bag phone.  After all, no need to have anything new or fancy for this.  Most of us have random old phones (perhaps even broken-screen ones) sitting around that would more than work here.

Nonetheless, the tech did work – and better than I expected it to.

Going forward:

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Now the tech geeks amongst you will probably smirk a bit.  Partially because it’s clever geekery, and partially because it’s not true offline caching in the same way Garmin caches iHeartRadio or Fitbit for Pandora, or Apple for Apple.  In that sense it won’t work if you don’t have internet access in some manner.  But ultimately, it does the job.  It simply does it in a rather creative technical way.  Waterfi has taken the ugly aspect of how to waterproof a Chromecast device and done it for you.  And because they aren’t developing any software here, that minimizes the number of things that could go wrong from a project timeline standpoint.  Not to mention the company has been around the block a few times, boasting some 200,000 devices made to date.

Of course, there are some obvious limitations here.  First is that you can’t change songs mid-swim.  The device is effectively a black box of magical music once you leave your gym bag behind.  For most of us, that’s actually not a big deal – because we’re listening to a longer playlist on Spotify (or whatever platform you’re using).  But, that means you can’t pause tracks either.  So if someone interrupts you to chat in the lane during the best part of the song…you’ll just have to tell them to talk to the hand instead.  Same goes for adjusting the volume.  One could look at the Waterfi variant of Mighty, which can do full offline Spotify and has buttons, but that means you can’t do other services, so it’s a bit of a tradeoff.

And finally – you’re dependent on your phone connection.  That, in turn, means that if the Waterfi device can’t talk well to your phone inside your locker, you’ll have to leave your bag somewhere on the pool deck (with phone inside), which might be vulnerable to theft depending on your pool.  Sure, some pool facilities may offer free WiFi, but I suspect that’s pretty rare.

Still, it’s a cool concept, and it will probably work for a lot of people – especially those that want Spotify while swimming.  And given the price – $129 on Kickstarter (again, their campaign ends Tuesday), it’s not a horrible price to pay.  Plus, you’ll still have a totally functional Chromecast Audio too (which normally costs $35 by itself), so there’s that for ya.  Not to mention I suspect we’re a long way off from any other viable competitor in this space that can do both Spotify as well as other services (like Apple Music), especially given how restrictive Spotify has been as of late.  Thus for now – this definitely seems like the best path forward.

With that – thanks for reading!


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  1. Tony Goncalves

    We have an endless pool in our house that my wife loves to swim in. We’ve been looking for ages for something to stream music to while swimming (ideally some sort of underwater speaker), but this looks like the perfect solution!

  2. Eric

    Hi Ray,

    Thanks for the early prototype review, very useful.

    Have you heard anything about this device which seems to be somewhat of a competitor to the one you just reviewed (although not exactly similar): link to kickstarter.com


    • Interesting, hadn’t heard of that one. Looks like they’re almost a year behind, though, with a more complete featureset. Certainly looks cool, but I suspect their approach (which is more complex) is probably behind their delays.

      The Waterfi approach (for better or worse), is actually silly simple tech-wise. Their limiter now is simply gearing up manufacturing.

    • Hey Eric,

      It looks like that project requires you to prep and download music from the web before swimming (like the waterproof Mighty.)

      This is from the project page:

      “Scott and Todd ultimately solved the problem of streaming music by avoiding the issue altogether. The Delphn enables swimmers to download their music onto the device for offline listening and swim with music to their heart’s content.”

      But the Swimcast does finally allow streaming music while swimming! This makes swimming with music as easy and convenient as listening to bluetooth headphones with your phone while running.

      Hope that helps clarify the differences.

    • gingerneil

      This looks excellent, and would meet my needs for Google Play Music while running… But 4 hours battery…!?!? £200!?!? Show stoppers!

    • Hi gingerneil,

      I love the enthusiasm! Where did you see the £200 price?

      The Swimcast is only £92 ($128) right now on Kickstarter (before shipping to Europe) and expected retail in the future is £107 ($149).

    • gingerneil

      Eren – sorry, I was referring to the Delphin that was linked above. I am a runner, and looking for an ipod shuffle replacement for streaming music services. Anything coming along that tries to deliver that can only manage battery performance levels that are pretty much useless for marathon/ultra use.

    • I’m a bit late to the thread, but I thought I would answer some questions posed here about the Delphin.

      The Delphin launched in July with good reviews so far. The Delphin works completely independent of any other device and connects to the internet over WiFi. The Delphin streams music, audiobooks, and podcasts using apps like Spotify, Pandora, Audible, and Apple Music. We did say on our project page that users should download music onto their device for swimming because we felt that most users would not have a quality WiFi connection at their pool. We have tested the WiFi in many pools and found that quite a few do actually have good WiFi. In fact, users can use a walkie-talkie app like Zello to coach a swimmer over WiFi while they are still swimming. Users can also use their phone as a WiFi hotspot if their pool does not have a great WiFi connection available.

      The Delphin also has a lap tracking app that we developed in-house. It will sync with Strava and our own lap tracking companion app (available for iOS or Android phones). You can track your swim history and speed over time. The lap tracking will tell you your lap count and splits at the frequency you choose in real-time during your swim. You can also use the tempo trainer aspect of the app to pace your strokes at whatever beats per minute you choose.

      We were able to increase the battery life of the Delphin to 6 hours of music listening time at full volume with the screen off. Unless you are pretty fast, it probably won’t last your entire marathon, but it is a 50% lift from what we promised in the Kickstarter. If you need a really long battery life, our SYRYN player actually has a 10 hour battery life (I need to update the product page of the SYRYN to reflect that).

      Let me know if I can answer any more questions!

      Thank you,

      Scott Walker
      Co-founder of Underwater Audio

  3. Ty

    Might want to check out another product that waterfi has out, the waterproof version of mighty. It is $165 on govx with .mil discount or $190 regular price.

  4. Jeroen

    What’s the quality/fit of the headphones? I bought a Speedo mp3 player a few years ago and their headphones didn’t work at all in the pool. These look no different from other headphones. Did they stay in easily? The most important part from my experience…

  5. Gearoid

    Could you use a Garmin to control the music?

    • Technically it should actually work within the connectivity constraints noted, I haven’t tried it though.

    • @Gearoid, that is a great idea actually, I honestly had not considered using my smart watch/garmin or an Apple Watch to control the phone. Duh!

      But like Ray said, they should all work within 10m or so of the phone. I’m going to post this idea as an update on our Kickstarter! Thanks for the idea.

  6. Mike St Louis

    Interesting and timely.

    I had the Sony waterproof MP3 player that you preloaded with songs. It worked for a while but started to flake out. I also found the sound level was pretty low compared to when I used it on land for running. Is that common when using headphones underwater?

    I did some searching and eventually found the Finis Duo player and ordered it through Amazon last week. I’m a little under the weather so I haven’t made it to the pool to try it so I can’t speak to how well it works. For those who don’t know about the product it uses bone conduction to conduct the sound to your ears through your cheeks. It straps on to your goggle straps so that it touches your cheeks. From the reviews I’ve read people say it works pretty good but have some issues with it not charging after a while.

    This product sounds good on paper but I think headphones are going to be a problem. Making sure water doesn’t leak in and making sure they don’t get loose while you’re swimming.

    • Blake Taverna

      I have one of the Finis and love them!! I could never get the ear buds to seal properly. I just put them over my ears over the top of my swim cap and it works a treat! If only there was something like this with jawbone speakers.

  7. MattB

    What no outdoor swim test in the canal with your phone in a DCR swim-float bag? Disappointed in you Ray! ?

  8. Dave Goss

    Is there such a thing as WiFi headphones? I would love a pair of decent over the ear headphones that have chromecast capability, waterproof unnecessary.

  9. AJ

    interested in all things techno-sports

  10. Phil A

    Looks like they sort of had a steaming device though it was Bluetooth, and I definitely cannot think of anyone who would want to wear something like it. Would loose streaming underwater probably.

    link to waterfi.com

  11. Tyler

    Instead of buying an extra remote, couldn’t you just use the music player controls built into several swim capable Garmins, like the vivoactive series?

    Or are those controls bluetooth (to the phone, not the music pod) and thus pose more of a challenge when the phone is so far away?

    • Royce

      Yeah that would work up to about 30ft (10m) because the watch controls the phone and the phone controls the Swimcast.

  12. So my Chromecasts won’t work unless I’m on WiFi. You mentioned turning on your hotspot to create a WiFi network that would then allow the Chromecast to connect. If one were to use an old phone (as a theft deterrent or prevention strategy) it would still need to have cell service so you could enable hotspotting, right?

    And if there was a pool or gym WiFi network, that probably wouldn’t work, right? Figure most public networks like that would block your ability to Cast…or not?

  13. Charles Morgan

    At the public municipal pool in my city in the United States, the rules of the pool are that no one is allowed to take any pictures of the pool. No pictures.

  14. Pete Lambertz

    Sorry, not buying it for me. Was interested in the music for swimming, but not interested in dragging my bag with out to the pool. I like to leave everything in the locker room which is behind 2 concrete walls and inside a locker. If I get pool tunes, I’ll get something that doesn’t need a phone/wifi.

  15. Lennart R.

    Since you are a Spotify user with a lot knowledge about sports tech, do you have any idea of why Spotify killed their running feature ? To me it was very valuable, and set them apart from other music streaming services.

  16. Tim Cruijssen

    So… no one commented on the Finding Dory soundtrack in the title picture? Love it! Besides talking about virtual fish, I would like to recommend the ´Sloterparkbad´ in the western part of Amsterdam. Olympic size, clean and people actually know how/when to stay in their proper lane. Marnixbad is my second choice (25m, but swimming at canal level).

  17. Pablo Gonzalez

    Hey Ray, have you tried the Mighty?

    • Spencer

      I haven’t had a chance to get a mighty yet but i am interested to hear how good it is. Also there are a lot of DIY guides out there to waterproof ipod shuffles (which a mighty is basically a new version of that) which i plan on doing when the time comes. So instead of spending 190 plus you could just get a normal mighty and waterproof it yourself.
      link to ifixit.com

  18. Hi Ray, that’s a beautiful pool in Zuid, but it is the worst to swim at!
    Try SwimGym at Wibaut, it’s the best!


    Is Chromecast currently supporting Apple music? Afaik, apple music streaming relies on airplay, which is not supported by Chromecast

  20. Ah, it would be great if the remote was waterproof, too. I don’t swim much but I do run (and sweat) a lot. None of the products I bought have held up for very long.

  21. Giles Roadnight

    I’m a little confused by the casting over a hotspot.

    When you setup the chromecast I assume that you have to connect it to your phone hotspot connection rather than your home connection.
    You then can only use that chromecast if your hotspot is on.

    Is that correct? It does seem like a bit of a round about way of doing it…

    • Mike St Louis

      I just means you are using your phone to create a WIFI network if you don’t have access to another one or if the WIFI signal is weak.

    • royce

      You can actually just use the same name and password for your home and mobile hotspot wifi connections and the Swimcast will be able to connect to your home network while at home and the hotspot while on the go.

  22. alan

    Does it work with Podcasts?

    • Hi Alan,

      There are a number of podcast apps that work with Swimcast! If you have an Android phone, then all of them will work because there is a “Cast” button in your quick settings drop-down menu that will stream any app you are playing!

      If you have an iPhone, I know Pocket Casts works. It’s officially supported by Chromecast Audio but I’m sure there are more, it’s just a matter of trying them out. The Apple Podcast app doesn’t work directly but there is a third party app called Caster that can send podcasts over from the Apple Podcasts app one at a time. It acts as a middleman.

  23. Nathan B

    Hi Ray,

    A slight workaround regarding changing volume and skipping tracks…

    My 935 has music controls for my CC audio around the house when using Spotify, so I guess it would work when you are within range of your phone at the pool?

  24. Joseph McLeod

    If you got a text message while swimming, would it play the alert sound your phone made? I go on call once every three weeks and quit swimming the week I’m on call because I’m afraid that I’ll miss the text alert I receive if I’m swimming. I’m wondering if this could be a solution for this.

    • Blake Taverna

      Hi Joseph
      I take the straps off my Apple Watch and tuck it into the back of my swim cap. When my phone rings it vibrates and on the plus side I can stop and take the call in the pool =)

    • Nathan B

      Not if you’re swimming in and out of Bluetooth range. Unless you happened to receive the message as you were in range.

      Not with my experience of the Chromecast Audio anyway.

  25. Tom

    Never swam with an IP67 proof cell phone with headset directly attached to it. Should also do the trick. Only hassle is were to put the device. Easy when having a tri swimsuit on, harder when swiming with shorts

  26. KKS

    Using swimcast innopen water swims, you need to bring your phone right?

  27. Mario guimaraes

    Have you herd about the the new JBL Endurance Dive?

    link to jbl.com

  28. Pete

    Have you seen or reviewed the FX-Sport VRX headphones for swimming? I have seen a lot of good reviews and they seem to offer a lot more functionality other than just music. A friend bought a set and seems happy. I wondered if you had come across them?

  29. SwimMama

    Is this product still available? Or are there any other similar devices on the market that you would recommend now?

    • Underwater Audio makes a product called the Delphin which can run Spotify, Pandora, Audible, or any other app on the Amazon Appstore. The Delphin also tracks your lap.

      Thank you,

      Scott Walker
      Co-founder of Underwater Audio

  30. vincent young

    So I can’t play Spotify songs on it without Premium? I’m wondering if I can upload music files downloaded from link to tuneskit.com. That’d be nice cuz I can’t wait to stream my favorite songs under water.