Shokz OpenSwim Pro Review

A sports headset that can also swim is not something the shelves are full of. Within Shokz's catalogue, a brand built on bone conduction, the OpenSwim Pro occupies a distinct place. Unlike most of its relatives, which are designed for running or cycling, this one adds a built-in 32 GB MP3 player to its Bluetooth connection — the only way to keep listening to music once your head is under water. The result is a hybrid, straddling dry land and the pool, and it was used over several weeks both in the water and out running to see whether that versatility holds together.

It is hard to mistake the OpenSwim Pro for anything other than a Shokz. The design follows the broad lines of the OpenRun range, with a flexible nickel-titanium alloy band covered in silicone that tucks in behind the ears without ever pinching. At 27.5 grams the headset is particularly light, which counts for something on a device that also has to serve as a music player.

Construction stays at the brand's high standard. The general sense of solidity is reinforced by the IP68 rating, which covers immersion to two metres for two hours, comfortably beyond what a pool session or a downpour demands. Comfort borders on the exemplary: the arms follow the shape of the ear and are forgotten within a few minutes, even during long sessions. Stability is there too, and once the headset is in place it is effectively impossible to shift, whether during a run or while swimming lengths.

There is one caveat. Because water offers far more resistance than air, the OpenSwim Pro tends to be pushed backwards during the first few lengths, which takes a short period of adjustment. Wearing a swim cap and goggles also has to be done in the right order, with the headset last, or there are unpleasant surprises. Tucking it under a swim cap to counter that resistance was tried, but the pressure that creates quickly becomes uncomfortable.

In the box are a silicone carry case, the proprietary magnetic charging cable and silicone earplugs intended for swimming. Only one size is offered, unlike the OpenRun Pro 2, but two colourways exist: black and grey, or navy blue and orange.

As with all of the brand's bone-conduction headsets, the OpenSwim Pro is driven by three physical buttons. On the left earpiece, the multifunction button handles navigation: a single press for play or pause, a double press for the next track, a triple press for the previous one. On the right, the volume rocker also handles power and pairing.

The smart part is the switch between the two listening modes. A long press on the left button moves the headset from Bluetooth to MP3 and back again. Better still, the playlist held in the internal memory starts on its own as soon as player mode is activated, with no further press required, which is a genuine benefit when your hands are occupied by a pool wall or a pair of goggles.

Beyond that, Shokz has tried to fit a maximum of functions onto only three buttons, at the cost of a certain complexity. Switching between playback modes — normal, shuffle, repeat — requires pressing the volume-up and multifunction buttons at the same time, a manoeuvre that nobody remembers first time. Once the right reflexes are learnt, the whole system works perfectly well day to day.

Under the shell sits a Bluetooth 5.4 chip supporting AAC and SBC, with multipoint so you can move easily between a phone and a smartwatch.

The Shokz app is very pared back: firmware updates, control customisation and a choice between two equalisation presets, standard and vocal. In MP3 mode a third preset appears, adapted to the aquatic environment.

The real limitation lies elsewhere, and it is worth dwelling on. To make use of MP3 mode — the only one that works under water, because Bluetooth simply does not cross the liquid barrier — the headset has to be connected to a computer by cable so that your own audio files can be dragged into its 32 GB of memory. It accepts a wide range of formats, including MP3, FLAC, WAV, AAC and WMA, which is more than enough for a demanding listener.

The problem is that at a point when almost all music sits on streaming services rather than a hard drive, having a library of files ready to transfer has become a real logistical challenge for many people. Without those files, the OpenSwim Pro turns into a silent headset the moment it goes under. That is very probably its biggest practical flaw. It is hard to hold entirely against Shokz, since the constraint is technical and no manufacturer's Bluetooth works under water, but it is a real obstacle for the ordinary user. An OpenSwim Pro 2 is already on sale in China and could eventually answer the point, since it works with the QQ Music service and can sync playlists directly over Wi-Fi, but Shokz has not announced a European release date, nor formally confirmed that the product will reach this market with support for Western streaming services.

The OpenSwim Pro carries two microphones per side, supported by two noise-reduction systems working together. In a quiet setting the pick-up is slightly recessed and a little less precise than on other models in the range, but no word goes missing at the other end.

In more hostile conditions the result is a pleasant surprise. The noise reduction does noticeably alter the grain of the voice as soon as the surroundings get busy, sometimes with identifiable metallic artefacts, but callers never had to ask for anything to be repeated, even in the middle of the street.

The voice remains intelligible in all circumstances, which is what matters for a hands-free kit. Only genuinely extreme situations, such as strong wind or continuous background din, eventually make the exercise difficult. That is an honest performance, consistent with what bone-conduction headsets generally achieve, a category that tends to be more effective on calls than the average conventional Bluetooth earphone.

Equipped with the brand's own PremiumPitch 2.0+ technology, the OpenSwim Pro performs close to the standard OpenRun. Unsurprisingly for a bone-conduction headset, bass is the weak point. The register is not entirely absent, and there is enough vibration to reproduce the timbre of a deep voice, but roundness remains very relative. There are no miracles to expect here, because the technology prioritises awareness of your surroundings over sonic impact.

Shokz's command of that technology nonetheless lets the device acquit itself well. Its extension into the bass is deeper than the average for the genre, which gives a sound present enough to avoid the impression of listening through a phone speaker. On volume, the OpenSwim Pro cannot make itself pleasantly heard in a genuinely noisy environment — the lot of every open headset of this kind — and can even generate some unpleasant vibration if the volume is pushed to maximum.

Under water the experience changes radically. Slightly disconcerting at first, the sound becomes deeper once you are fully immersed, with more loss in the treble but also a rounder and more powerful delivery. This is clearly where the headset is most at home. The supplied earplugs are worth using to keep out parasitic water noise.

Shokz quotes 9 hours of battery in Bluetooth and 6 hours in MP3 mode. Under standard conditions at moderate volume, those manufacturer figures are broadly respected, with close to 8 hours 23 minutes recorded over Bluetooth and 5 hours 34 minutes in MP3. Bone conduction consumes a great deal of energy, which makes the headset very sensitive to the volume used: making it vibrate harder places a heavy demand on the battery.

One small regret concerns recharging. Rather than adopting the now-universal USB-C port, Shokz continues to use a proprietary four-pin magnetic connector, which handles both charging and the transfer of audio files. That choice does improve water resistance and limits the risk of corrosion, but it means always keeping the cable to hand.

This is a headset for swimmers and runners who want one device for both, who prefer to keep their ears open to what is going on around them, and who are willing to build and maintain a local library of audio files. Anyone whose music lives entirely on a streaming service should think carefully, because the underwater half of the proposition depends on files you own outright.