Question Am I wrong to not want a modern computer?

[justinthedeeps]

Shearwaters so good tho #nerdlust

 

[Belzelbub]

No, they did not have dive computers running those models in the 90s, but the models themselves did not change since early 2000s.

The algorithm hasn’t changed, but the algorithm is not the entirety of the software or firmware on the DC.

Being able to update the firmware if the manufacturer releases a patch to fix a bug is a good thing. Sometimes, those firmware updates introduce new features that have been requested by customers. Assuming, of course that the manufacturer is listening to their customers. After purchase of both my Garmin and my Shearwater, the manufacturers have released new features. At least a few of those are features that I like. I have those features because the manufacturers allowed me to update the firmware.

To the OP: Apart from a couple old computers (Uwatec in particular), an old computer will keep you plenty safe. There have, however, been enhancements over the years. It’s up to you to decide if they are worth it.

Algorithms haven’t changed much, but that doesn’t mean that the algorithm in your older Suunto is the same as a more modern DC. For one, computing power has increased, which allows the DC to run a more complete version of the algorithm. Another notable change is that, in recent years, many manufacturers are offering some (if not all) models running Buhlmann with Gradient Factors. That’s telling. Many even offer custom GFs allowing the user to choose the conservatism they want.

Screens are a big improvement. I much prefer color screens to an old light gray and darker gray LCD screen.

Alarms. Audible alarms suck. Sound travels differently in water, so it’s tough to tell who is beeping. Haptic alarms are much better. No mistaking if you feel that vibration on your wrist.

Batteries. Easily user replaceable, or rechargeable are more the norm these days. As opposed to the days of soldered battery leads and oil filled DCs that require a bit more skill.

Connectivity. I used to have a problem logging my dives. I didn’t see the point in writing things down on paper. With electronic logs and downloadable dives, this changed for me. I do see the point with an easily searchable log.

Upgrades. I see this as a huge plus as mentioned above. Especially if it can be done without the use of a proprietary cable. Software sometimes has bugs. That is true today, just as it was when your Suunto was made. Being able to address them is good. With my Shearwater, I need to actively update it via Bluetooth connection to Shearwater Cloud. It’s simple and trouble free. My Garmin is even easier. Occasionally, I’ll get a haptic alert. The screen lets me know an update is available and asks if I’d like to update now.

 

[dmaziuk]

The algorithm hasn’t changed, but the algorithm is not the entirety of the software or firmware on the DC.

No, it's only the DC's primary function.

Don't get me wrong: the more software you put in the system, the more bugs you get, and if you look at the apps available for Ratio, you can easily see why firmware updates are a crucial feature there. I would want them too if I were a Ratio user.

OTOH my old Seiko watch that only computes no-stop time and deco stops, whose firmware was implemented correctly in the first place and had no reported issues in the 20 or so years it's been around... well I can't play angry birds on it during the safety stop and can't upgrade it to angry birds Rio either.

 

[Germie]

You use the old Viper, one of the modells that gives you deco under the shower.

These old computers work ok for single dives. Maybe ok for a simple second dive of the day. But as soon as you are going to do more dives in a day or a week of diving, reverse profiles, ignoring safetystops, etc, they give you very short ndl's and go into deco way too fast.
This can be annoying in a group on a liveaboard, that you are the one that shortens the dives of others.
But in most cases you can use your old computer, no problem.
The problem is that a lot of divers see NDL as a rigid number. But this is not true. If you look at DCIEM with 15 minutes at 30m as NDL on air, and padi/naui with 20 minutes at 30m on air, there is 5 minute difference. This is just a table. But 5 minute is a lot, especially if you are on a nice wreck and the dive is an expensive holiday dive. Then for sure I will not go up if computers of others show 'deco' and mines not.
If your old computer is showing deco, then you must wait, otherwise you have a '505'.
Conservatism is not bad, but the old Suunto's showed tooooo much conservatism.
So as long as you don't do a lot of dives, you computer will be ok.

The funny ting is that most computers in the budget pricing cannot get software updates. You buy them, use them, and updates are not there.

The basics of buhlmann or rgbm or vpm are already for years the same. It is only implementing that causes differences and then you maybe need or want software updates.
Remember that a softwaretester cannot test all things and all bugs out. So users are most times the real testers and then always bugs are found. An update is then a nice option (says someone that almost never updates computers and for sure not if the computer works for me perfect, as updates also can cause new failures). And remember if an update is coming, don't want to be the first to use it. I have seen problems with updates also a lot (for example ap, after an update batteries were drained fast, this was just software, but really annoying), or updates that blocked computers.

So conclusion: use your computer if you are not a diver that does a lot of diving in a day or go every day diving. Then you won't find any problems.
If you do more dives a day, more days behind each other, strange profiles, etc, then an other computer is adviced, or you are the one that has to wait long under water where others already have had a beer

 

[Jai Bar]

The basics of buhlmann or rgbm or vpm are already for years the same. It is only implementing that causes differences and then you maybe need or want software updates.

Buhlman's algorithm is based on Haldane's compartment model circa ~1908.

RGBM was developed by the late Bruce Wienke in the 1980s and has got nothing to do with compartment models whatsoever. Not the same for years. Or, if I misunderstood and you meant that neither of them has changed for many years, then this is correct.

You use the old Viper, one of the modells that gives you deco under the shower.

I have been taking showers with Vypers for almost two decades and never had any problem. There is some annoyance with the Vypers that I had owned is that after the dive they stay on "AC" and although they count the time as surface interval when out of the water- including shower- the display does not turn off. I had once ever seen this causing a fluke when after diving in the gulf of Aqaba red sea then driving to the dead sea (400m below sea level) that the computer entered diving mode at depth of 0.5 meter. Not sure what other computers would have done in similar conditions.

These old computers work ok for single dives. Maybe ok for a simple second dive of the day. But as soon as you are going to do more dives in a day or a week of diving, reverse profiles, ignoring safetystops, etc, they give you very short ndl's and go into deco way too fast.
This can be annoying in a group on a liveaboard, that you are the one that shortens the dives of others.

Wife and me have been diving dozens of safaris with Vypers and the only thing I can tell is that in order not to prolong other divers waiting for us in the RIB or Dhoni etc we always jump first and always come back last. Never had to hinder or shorten other divers' dives because we used a Vyper. In my experience the most common cause for divers to shorten time for the group is always someone with fast air consumption, not because of a Vyper.


I am by no means a Suunto fanboi, they have probelms and annoyances like the one mentioned above, plagued by depth sensor problems and so on. But RGBM is an established algorithm and this thing about being too conservative is only partly correct and for the casual recreational diver- even in groups/safari/etc. in most cases not a problem.

 

[rongoodman]

I am by no means a Suunto fanboi, they have probelms and annoyances like the one mentioned above, plagued by depth sensor problems and so on. But RGBM is an established algorithm and this thing about being too conservative is only partly correct and for the casual recreational diver- even in groups/safari/etc. in most cases not a problem.

Suunto and a few others have promoted multiple algorithms over the years labeled as "RGBM", some on computers which clearly lacked the power to run it, so the question then becomes "What are you actually running?" and they won't say.

 

[Jai Bar]

Suunto and a few others have promoted multiple algorithms over the years labeled as "RGBM", some on computers which clearly lacked the power to run it, so the question then becomes "What are you actually running?" and they won't say.

"Power to run it"? These are not smartphones with an operating system that runs applications, or a windows machine.

Diving computers such as Vyper are electronic devices based on circuits that do only one thing: calculate values based on inputs from clock and depth/pressure sensors. Like a good old high school casio electronic calculator.

For years most dive computers in the market from several brands were actually using Seiko OEM integrated circuit boards. These were completely hard wired, no firmware and no "bug updates" nor "new features".

 

[JMarc]

For years most dive computers in the market from several brands were actually using Seiko OEM integrated circuit boards. These were completely hard wired, no firmware and no "bug updates" nor "new features".

I strongly doubt that any digital dive computer had its decompression procedure hardwired and not in firmware, even microprocessors have firmware (usually named micro-code). I don't doubt that firmware updatable without returning it to the factory is much more recent.

I'm aware of the existence of analog dive computers (for instance the Canadian navy had their own, but they started to use digital implementation in the 70s) but those another kind of beasts.

 

[dmaziuk]

RGBM was developed by the late Bruce Wienke in the 1980s and has got nothing to do with compartment models whatsoever.

That is simply not true. They are all built on tissue compartments and half-times, the only difference is in on-/off-gassing function. For "straight Haldanean" like ZH-L it's the straight log(2) of delta-P. Wienke modifies that with "Gradient Reduction" fudge coefficients, Thalmann changes that to straight line under certain conditions, and so on.

 

[Germie]

In Suunto computers you will find 'fused RGBM'. This is another calculation of more or less RGBM, but what exactly is 'secret'. The older Suunto's had different 'RGBM' than the newer ones have.