Scubapro Meridian dive computer

Freediving with the Scubapro Meridian - A Review

What is the Scubapro Meridian like for freediving? An unfinished product or a raw diamond?

The Scubapro Meridian is an advanced watch-size dive computer that offers a Scuba-, Gauge- as well as an Apnea mode which targets a group of users who want to scuba dive as well as freedive, both potentially to an advanced level, as features like gas changes and a depth rating to 120 metres suggest.

In our tests, we used the Meridian in our own freediving training, during courses in pool and open water and as judges in all disciplines during the Andaman Freediving Challenge 2013. We have not tested any SCUBA functionality. 

To start with the bad news: Probably the most irritating issue while testing the unit was that the lack of documentation of the apnea mode of the Meridian. A stark contrast seeing a campaign that advertises the unit's documentation. It took a lot of puzzling - even for representatives of Scubapro - to figure out what the computer was doing and what it was trying to tell us. Apnea mode is hardly documented at all in the available manual and in at least one place the documentation seems to disagree with the actual implementation. So there was a lot of trial-and-error and guesswork before we had a semi-decent idea of how to use the computer. We hope that this article will help new or prospective users to get started with the device.

Hardware and Display

The hardware is one of the most convincing arguments for the Meridian. We highly appreciate that standard wrist straps can be used with this very solid unit made from stainless steel. The buttons operate very smoothly with no tangible or audible 'click'. The relatively heavy unit feels reliable and is well-sized, slightly smaller than most watch-style dive computers.

The blocky digit-based display will look prehistoric to Suunto users, yet it is surprisingly easy to read. The fancy-looking backlight display works well in the dark while its effect is nearly imperceptible in normal and half-light. The cryptic and very small icons on the display are not easily recognised in their function, but one does easily get used to associating 'the blob in the upper right corner' with no-fly time (which is also applied in freedive mode - see below).


We were very happy to see a computer that shows the speed of descent and ascent in freediving mode and and even an alarm to be set for maximum speed of descent, ascent or both. Separate values for descent and ascent might be a nice touch, but what the Meridian does at the moment is already a very nifty feature.

The choice between the plethora of alarms is very welcome. Only a few of them at any given time are discernible when used together, for the sheer number of well-audible beeps that fill the water with all alarms enabled. All the basics are there and some that we deem quite useful in advanced freediving. And there's the low-heart-rate alarm that is essentially a non-feature, as we want a low heart rate and the last thing we want then is an alarm. Apart from that, a well-trained freediver will easily slip below the minimum rate of 30 bpm during a dive.

  • Depth notification
  • Max depth alarm
  • Depth increment notification (min. 5m)
  • Max Speed alarm (ascent/descent/both)
  • Low heart rate alarm (...)

A sample frequency of 4Hz (4 samples per second) and the ability to set the precise water density in grammes per litre is a great feature for competitive freedivers and judges who rely on precise depth measurements. When using the Meridian as the official depth gauge in competition, we got extremely precise readings and will happily use a Meridian as the official depth gauge again just for this feature alone. The additional (and redundant) salt-/fresh- water switch only adds confusion here.

The ability to manually start logging a dive that has been pointed out to us as a key feature of Apnea mode is nice in theory, but only of very limited use in most dives, as the dive computer is the last thing most freedivers want to think of when starting a dive. A very elegant use case for this feature is to have one's buddy/coach use this functionality in order to have a static dive in the unit's log. 
When the optional heart rate monitor comes into play, this feature is very interesting indeed, as the unit also logs the heart rate in its profiles (along with depth and temperature). In our test, we used a Polar heart rate belt which worked nicely with the Meridian.

Especially in this use, we would have liked to be able to set markers in the profile for start of breathe-up, start of dive, onset of contractions, etc., which in the manual is mentioned for scuba mode, but does not seem to do anything other than emitting a beep in freedive mode.

Session log instead of individual dive log. After being somewhat surprised by this policy, we have found it quite enlightening to see that the computer's log also keeps track of the surface time and one logged "dive" actually shows a complete session with the individual dives in context to each other, yet again the software falls short of the computer's potential, as it is impossible to see the details of the individual dives in the log book, so the computer's 4Hz sample frequency goes to waste, as the software does not allow us to zoom in and see the dive profiles at this level of detail. ( Keep reading for for a workaround on this limitation.)

Compared to ...

In comparison with other combined scuba- and freediving computers, the Meridian roughly plays on par with the Suunto D6i for functionality and surpasses it in the quality of the hardware itself. While the Suunto computers have a very good implementation of a freediving mode and intuitive user interface to show in their favour, the Suunto hardware policy - especially concerning the wrist straps with their bad reputation for reliability - is far less convincing. This may avert even potential buyers who like the D6i's matrix display and intuitive user interface design.

It is easier to fix flaws in the software than hardware design, so there is a good argument for the Meridian, given the one assumption that Scubapro will actually work on and release updated and fixed firmware for their product. The Meridian easily outclasses the Oceanic Geo that we have tried and even more easily the Tusa Zen 2.0 with its horribly cryptic UI and the inability to set the exact time, which renders it useless in competitions. Only the Geo's N₂-calculation in freedive mode - a feature for several years - one would expect in advanced freediving computers like the Meridian by now.

Some Issues in Detail

48-hour lock-out from SCUBA mode after freediving. Scubapro play it safe with their computer and apply a 48-hour lock-out from any scuba mode after any logged freedives. For most freedivers, this is overshot, but we are happy to see that Nitrogen-related risks are recognised and acted upon. Those freedivers who know that their dives do not introduce an increased risk can override this lock-out in the DESAT option in the menu, which prompts the user to enter the Scubapro-specific security code "313" to make sure that this safety feature is not overridden by accident.

Counter-intuitive button operation. This will - sadly - take some getting used to until Scubapro's development team have fixed the issues in the Meridian's user interface. For some menu items, pressing the [-/down] button will move one level up in the menu hierarchy, effectively doing what we would expect from pressing and holding the [Select/Escape] button (bottom left).

This becomes more annoying, when one contemplates how unnecessary a usability blunder like this is, but is relatively easy to get along with in the real world.

Time unavailable in apnea mode, it is not possible to see the current time, nor the total session time while in apnea mode, so leaving dive mode is the only option when one wants to schedule a training session. To do this it is not - as one would expect - pressing and holding [Select/Escape] that exits dive mode, but instead one has to press and hold [-/down] to exit the dive mode and get back to the menu system. This function also splits the dive session, which has an effect on how the computer logs sessions and dives. Use this (dys-) function to get a detailed profile for a target dive - at the price of splitting your session log.

Stop watch does not recall split/lap times. The stop watch shows lap times while running (for 5s), but it is impossible to recall these times after stopping the timer. This is a significant problem for blind operation e.g. in teaching or when judging, when the user does not want to look at the watch while taking lap times. In most training situations, the stop watch is adequate but when judging, the stop watch functionality is insufficient and another stopwatch is necessary. The ability to see the exact time (including seconds) in stop watch mode would also be much appreciated.

Apnea log,  in-unit and on the PC. The computer does not show individual dives, unless it is tricked into this behaviour by ending the session pressing and holding the [-/down] button (NOT the [Select/Escape] button). What the unit considers a "dive" is in freediving more commonly referred to as a dive-_session_, so the log will show a summary of the session, including maximum depth, number of dives, longest individual dive, temperature and duration of the session in minutes. - This redefinition of the concept of a dive is very confusing in the beginning and renders the in-unit log somewhat useless for dive analysis for training purposes other than proving bragging rights on achieved depths or times.

When scheduling training sessions, the session time turned out to be quite useful and it would be even more so if it were visible in dive mode.

Unintuitive Menu entries for settings. In its current implementation, it is visible that Apnea mode is a mere add-on to a computer that is built around scuba functionality. Menu entries that apply to both scuba and freediving or are specific to apnea mode are freely sprinkled among the unit's scuba- and gas- settings, while there is no submenu for general settings that would introduce some more logic into the settings.

USB cradle as an option. Since the on-board log of the Meridian is almost useless, the cradle is essential for anyone who wants to use the computer's logging functionality. As such, the USB cradle is an integral part of the Meridian's functionality and should be bundled with the unit. (For this reason, we offer the Meridian in exactly such a bundle.)

Key findings for the User's Orientation

  • Basic general setting for time, alarm are in a completely separate menu that is only available when pressing [Select/Escape] in watch mode
  • Heart rate monitor settings are located in the GAS- and APNEA- submenus.
  • Water activation is hidden in the SCUBA submenu. TuIgnoring the SCUBA features, trning water activation off does not switch off dive mode, as we would have hoped. A shortcoming that Suunto fixed in their recent firmware update for the D4i, D6i and D9tx computers.
  • Water density can be set precisely (in grammes per litre) in the APNEA submenu, while there is also a salt/fresh water switch in the SCUBA submenu. - We are not sure about the implications of this dual settings situation.
  • The duration of the backlight is set in the SCUBA submenu, as is the attention beep. (We would expect this in the basic watch settings)
  • The lock-out after freediving can be overridden via the "Desat" item in the GAS submenu

There are a few more minor oddities in the handling of the Meridian, but these are the main ones that a freediver may find themselves looking for in the beginning. Most of these are quirks that may well be described as 'adding character' to the Meridian, but it is very apparent that Scubapro needs to put some more love (and testing and logic) into the Meridian's user interface to make this unit as attractive to freedivers as it could be.


The Scubapro Meridian is a decent freediving computer. This comes as a big surprise to us, as its interface is full of bugs that are even more annoying because they are so avoidable and easy to fix.

It turns out that in the water, the computer does almost everything we need when teaching and almost everything we want even in advanced training,  while adding some advanced features that we have not seen in a freediving computer of its size. These advanced features however are clumsy to use at best or even crippled by the computer's interface. Functionality like the heart rate monitor and display/alarms for speed of descent and/or ascent make the Meridian stand out.

Add to that the computer's solid hardware with its  trust-inspiring weight and feel and the reliable wrist strap of choice that removes the ever-nagging doubt about Suunto's breakage-prone plastic straps and you have a computer with a lot of features potentially outperforming the Suunto D6i at roughly the price of a D4i.

Scubapro have been putting an image campaign behind the Merdian's release, working towards a product that gets in line with Suunto's all-time favourite Stinger. If they actually want the Meridian to join those ranks, they will likely want to put the (comparatively little) work into some firmware fixes that could well turn the Meridian into a milestone product. We are hoping they will realise this computer's huge potential.

Whether the Meridian is a raw diamond or will remain an unfinished product now depends on how Scuabpro manage their product support.

We would like to explicitly thank Guido Mainardis, the Scubapro representative of Water World Asia who has provided us with test units and tons of support and help during our adventures with the Scubapro Meridian. Without him, we would never even have thought about trying out the Meridian and we are happy that we got the chance.