Altitude Issues

I will say up front that I am not a Garmin employee.  In fact, if you look at my posts in this forum you will see how often I am scathing of Garmin: their poor communication, lack of transparency, and general poor development competence.

Determining altitude is a completely different prospect from determining depth.  Water does not compress and so there is a linear relationship between pressure and depth.  If you know the water type (fresh water vs seawater) and pressure you know the depth.  Even cheap pressure sensors are accurate for measuring depth as can be seen by the cost of relatively cheap dive watches.

I have done well over 200 dives with my Mk1 and the depth readings have always been accurate.  I actually dive with three other devices that measure depth and every time I have compared them (using the log data) they have been within centimetres of each other.  They will never be 100% the same as it is impossible to keep all four devices at the exact same depth for the duration of the dive.

More importantly, the no decompression limits (NDL) closely align between my Mk1 and my Shearwater Perdix, both running the same algorithm and conservatism.  This is based on pressure more than depth.

Determining altitude is a whole other issue! You can't just rely on pressure as barometric pressure comes into play and must be taken into account.  How do you measure one without the other?

I will agree that altitude on my Mk1 is not all that accurate but it is close enough for my requirements.

As far as diving at altitude is concerned it doesn't matter a whole lot as it is the relative pressure from the surface to dive depth that is important for tissue loading calculations.

So for diving, the Mk1 is safe and reliable.  

Do you own a descent mk1,(Goose)?

I was planning on buying one as I'm a PADI SI and have been a Garmin user for other sports for many years, and whilst I've had issues with other Garmin products they have been more of the buggeration factor and extraordinary inconvenience kind rather than potential life threatening kind.  

Having experienced, to my mind at least, a significant issues with my fenix, and considering the response/support/assistance I didn't get from Garmin I no longer have faith in the brand when it comes to a device I would have had to rely on for my personal safety.  That said, I am in the habit, and would still have had a secondary dive computer with my anyway, however I'm not prepared to spend 1k and have it break on me as my fenix has.

I am quite prepared to wait 5 or 6 years and see the long term use data on the new generation of dive computers from 'new' market entrants and in the meantime trust myself to brands I know have a depth of knowledge and history of performance under the water.

I am technically interested in the architecture of the device, the sensors etc and would love to understand better how they work - if anyone does know please share.

Goose said:

I am quite prepared to wait 5 or 6 years and see the long term use data on the new generation of dive computers from 'new' market entrants and in the meantime trust myself to brands I know have a depth of knowledge and history of performance under the water.

You mean like Suunto and Aqua Lung?

https://www.deeperblue.com/suunto-settles-class-action-lawsuit-for-certain-dive-computers/

Interesting link - I take it you've actually read it?  An out of court settlement which only applies in the USA and only if your device was bought through Aqua Lung as the distributor?  Interesting that Suunto deny publicly any issues with the products, also very interesting that this claim has only been brought as a class-action in the USA.  I would have thought any real issues would have brought in the USA equivalent of health and safety, advertising standards and if true, would have led to a world-wide recall.  Perhaps I'm missing something, but the article, and judgement makes no comment on the veracity of the claim, only that if you purchased one of the products listed you are entitled to an assessment and possible replacement if it is found to be defective.

I'd love Garmin to offer the same without the need, cost and effort of a class action lawsuit (civil lawsuit, not criminal lawsuit).

I have made it clear that my issue and concern is the long term reliability given my own experience, and that of the many hundreds of others who have been posting about the exact same issue for at least 5 years across all versions of the fenix range - I have been offered no technical info to assuage my concerns about the architecture of the Descent - in fact I am told by Garmin that they reverted to the fenix 3 casing and structure for the Descent, so why would I invest in it knowing that the altitude/barometric sensor and data will most likely fail?

Again, if I cannot trust one set of data and sensors - pretty sure I don't want to trust the device as a whole.

My choice not to purchase and my choice to share my experience - make of it what you will, personally I would have been grateful for a user forewarning me about the potential risks in purchasing a fenix if only I hadn't been so eager to buy when they first came out.

An update for you - and thanks again for your comment above - I'm relieved to hear that the devoice works as intended below the water, although it does make it a rather expensive depth gauge if that's all I wanted it for...

As to my fenix issue - after a month of back and forth with Garmin they requested screenshots of the data fields in the sensor set ups and have accepted that the device needs to be replaced, and are replacing it.

It has taken me a month, four or more different 'agents' and an escalation to reach a conclusion, so good for Garmin for finally providing the support.  However, I would have expected that level of customer care from day one, not after a month of me having to chase it.

I'm still not convinced I'll buy a Descent, much as I want to,  as I'd want to use it as replacement for my fenix and I have yet to be convinced that there is any recognition by Garmin that multiple fenix devices are being reported to have the same issue as the one I've reported (google search Garmin fenix altitude issues).  No one can demonstrate to me that the architecture of the Descent isn't the same as the fenix with a depth/pressure sensor and pretty software.  If anyone knows of a site that has deconstructed it and studied it, I'd be interested in learning more before spending 1k.

If this were a medical device it would not be approved for sale.

No - I was considering it, in fact had placed an order, but since cancelled it when I discovered the number of complaints about the same issue I have with the altitude/barometric pressure sensor.

I use MK1 for almost a year with various multisport situations including diving. The Altitude issue is very frustrating. I totally lost confidence in MK1 ability to accurately display altitude, and with that not so sure if other values are accurate... Examples:

Biking 1 - same start/end point - starting point at 200 feet altitude, hour later coming back to the starting point and the altitude is reported as 300ft

Biking 2 - same start/end point - starting point at 50 feet altitude, two hours later returning to the starting point and altitude is reported as -15 ft (yes, below 0)

Skiing - skiing the same peek with max of 4000 feet, each run the same peek gets higher and higher, at the end of the day the peek becomes 5500 feet above the sea level....

Sleeping - yes, need to mention that my own bed in my own bedroom location altitude is fluctuating between 50 feet and 200 feet above the sea level...

I am on the marked for the cycling computer and various sensors. Based on my experience with the MK1, I am not considering any of Garmin devices. I would love all to integrate and work together, but...

I will say that my experience with the edge 810 was and still is excellent.  Never had a problem with it for cycling, but like you have had the same issues with my fenix as you do with the Mk1.  I upgraded to the Edge 1000 and also didn't have issues with the altitude - the biggest bug bear was the battery life - you effectively have to disable practically all the functions  in order for it to last more than 4 hours on the road, and there is no way you could use it as advertised!