Reasons NOT to Use a Computer for a New Diver?

[boulderjohn]

I've had a number of citizen watches fail over the years and had one stolen. After getting tired of spending a bunch of money on dive watches I bought a €30 Casio that's water tight to 200m and has a 10 year battery. I've had it for about 3 years and I'd highly recommend it. The whole cost of this watch is about 1/2 of what it takes to get a citizen battery changed and... the best part... it works as advertised!

Water tight?

If you look at this Wikipedia site that talks about water resistance ratings, you will see that the designation "200m" can mean different things, depending upon whether it is a designation for "water resistance" in a watch or for a designated dive watch. There is a chart at the end.

Or you could go to Casio's own chart. In it you will see that a watch that is designated as water resistant to 200m actually means the following: "Wearable around sinks, during swimming, snorkeling, jet-skiing, but not scuba diving." Below the chart, it says, "*Only watches marked with the words "DIVER'S WATCH 200M" can be worn while scuba diving (with air tanks)." The designation "with air tanks" is important, because the chart says that even a Casio watch identified as a diver watch is not suitable for depths requiring the use of helium gas.

I just surfed the catalogs of a number of stores selling Casio watches, using the required phrase "DIVER'S WATCH 200M," and I saw a lot of them advertised as "dive watches," even though the official Casio site linked above does not give them that designation. Some of them were not even close to being that--I saw 100m and even 50m "water resistant" watches under the heading of "DIVER'S WATCH 200M."

I think it's pretty hard to tell what you really have unless you carefully read the literature that came with your watch.

 

[Diver0001]

I think it's pretty hard to tell what you really have unless you carefully read the literature that came with your watch.

Fair enough. I've made over 100 pool dives with it and I'd still recommend it, at least for that.

R..

 

[gcarter]

Water tight?

If you look at this Wikipedia site that talks about water resistance ratings, you will see that the designation "200m" can mean different things, depending upon whether it is a designation for "water resistance" in a watch or for a designated dive watch. There is a chart at the end.

Or you could go to Casio's own chart. In it you will see that a watch that is designated as water resistant to 200m actually means the following: "Wearable around sinks, during swimming, snorkeling, jet-skiing, but not scuba diving." Below the chart, it says, "*Only watches marked with the words "DIVER'S WATCH 200M" can be worn while scuba diving (with air tanks)." The designation "with air tanks" is important, because the chart says that even a Casio watch identified as a diver watch is not suitable for depths requiring the use of helium gas.

I just surfed the catalogs of a number of stores selling Casio watches, using the required phrase "DIVER'S WATCH 200M," and I saw a lot of them advertised as "dive watches," even though the official Casio site linked above does not give them that designation. Some of them were not even close to being that--I saw 100m and even 50m "water resistant" watches under the heading of "DIVER'S WATCH 200M."

I think it's pretty hard to tell what you really have unless you carefully read the literature that came with your watch.

3 years ago I emailed a question to Momentum / St Moritz and received this response:

The M1 DEEP 6 is not tested to an ISO Standard.

The ISO 2281 standard is the one we publicly announced, as it involves a simple water-resistance test conducted once on a new watch, at a given static pressure. The ISO 2281 test can be administered at very low pressures (30 meters) so it does not necessarily mean that a watch is suitable for diving (though it is worth noting that our M50-DSS model is actually tested to 500 meters). There is no doubt that a more appropriate test for qualifying a diving watch for repeated usage at a variety of depths and pressures would have to include safety margins, an accelerated aging test of the seals, take into account the effects of rapidly changing water pressure and temperature, as well as dynamic mechanical stresses encountered by a watch.. The ISO 6425 standard requires an exhaustive battery of tests over a prolonged time: there is little doubt that it would be a better measure of the performance of our watch. However…. the tests required for the ISO 6425 standard would need us to set up ongoing, lengthy testing for every production. These would have to include magnetic tests, shock resistance tests, long immersion in high-saline water, immersion in corrosive liquid, special pressure tests where high pressure is applied, then removed very suddenly, etc., etc.… you get the idea.

Our assembly is not set up to do this and we have been quoted a very high cost to include the complete range of tests in our production and QC process. As this would drive up the unit price of each watch significantly and increase production lead-times, we elected not to implement it. This conviction is based on the large number of serious divers using our watches, and on the fact that we use only the very best vendors for all components that go into our product. It is of course a paradox, that if we use very high grade and expensive components to make a better watch, we need to spend even more to put it through more rigorous testing, if we wish to have the enhanced quality “certified”. For now, and given our target price range, we have chosen to keep the retail price as affordable as possible, and let the durability and reliability of the product do the talking for us.

Kind regards,​

Perhaps this might offer some insight as to why Casio provides the caveats as well. Because they are unwilling to spring for certification in order to be able to use the appellation in order to keep the watches affordable does not mean that they can't do the job - obviously, as many do use them for scuba.

My reading suggests that 200M resistance is the minimum that should be considered.

Some more on the ISO 6425 standard:

Divers Watch ISO 6425 Water-Resistant Standards... - Watch Freeks

 

[tracydr]

I agree that some of the dive computer manuals can be miserably difficult to learn from. And that the Dive Nav. courses online can be quite good; I took one on a computer.

The Atomic Aquatics Cobalt has a really nice interface.

People speak highly of the simplicity of the Shearwater Petrel interface, but be mindful there's no air-integrated option.

I believe there are some other computers that have interfaces more like a smart phone and less like a digital wrist watch. The LiquiVision Lynx has a tap interface; you might check whether it uses menus.

I will say the better interface products tend to be pricy.

Big question: will you dive often enough to remember how to use the thing from one trip to the next?

Richard.

Liquivison has an easy to read manual and the XEO is a great computer. I do wish they had a Dive Nav course. The computer is so easy to use,easy to read, very intuitive.

---------- Post added October 26th, 2013 at 01:44 PM ----------

Apparently you have never seen an entry level Suunto computer. It's not hard to understand and it's nowhere near $1000.


Ever stop to consider that you were not taught how to use your computer because you didn't take a computer-based course?


Your area may prevent divers from doing multiple dives, however in many tropical locations it's pretty much the norm to make two (or more) hour long dives/day. New divers will benefit from longer bottom times, putting their newly learned skills in to practice.

The price of dive watches may vary considerably but approx $75-$100?
A wrist mounted analogue depth gauge is $72 at LeisurePro.
Suunto Zoop = $250

Using a computer does not prevent divers from working on "buoyancy, trim, planning, or sticking to the plan". Dropping that in here is a Strawman.

It doesn't really need to be a dive watch. For years, I used a cheap timex watch from Walmart rated to 100 meters for several years before it started to leak as my timer. An analog depth guage and SPG. It was a very cheap option that worked for quite awhile, until I could afford a computer. Of course, in the mid-nineties, computers were relatively expensive and not as user friendly.

 

[boulderjohn]

It doesn't really need to be a dive watch. For years, I used a cheap timex watch from Walmart rated to 100 meters for several years before it started to leak as my timer.

Just a reminder of what that means for people who did not follow the link above:

Water Resistant 10 ATM or 100 m: Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. NOT suitable for diving.

If you use a 100m water resistant watch, it may work. Or it may not. It may work for a while while under water, stop for a while, and then start again, giving you a skewed idea of how much time you were under water.

 

[tracydr]

I can't find a good reason not to either. However, several have made good points about getting to know the tables and learning how to use them. But here is something too, which several posters came close to saying, but it didn't come out that way even if they were thinking it.

And this is going to be dark folks so if you are squeamish stop reading for a minute okay. But, post dive accident analysis. Computers can aid in investigating dive accidents and incidents. They can even help doctors in determining severity of DCS and applying the computer data to re-compression treatments. If you dive tables there is little to no data to tell anyone your dive profile. Sure they maybe a bottom timer and a depth gauge, but those only give a small sample of the actual dive profile. They don't tell anyone how long you stayed at XYZ depth etc. etc. So, I think computers have WAY more going for them than running tables. B.

Actually,bottom timers do give a great deal of data. The Liquivision bottom timer gives almost as much data as many computers,more than a lot of computers.
I understand what you're saying but many of the more expensive bottom timers are basically computers. They just don't have decompression algorithms.

 

[PfcAJ]

Casio watches are the only digital watches I've come across that survive. Particularly great are the g-shock series, and they are not 'rated' as divers watches.

I've had my g-shocks in some pretty sporty environments (both topside and underwater) with never even a hiccup out of them.

Top notch gear.

 

[drrich2]

Water Resistant 10 ATM or 100 m: Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. NOT suitable for diving.

Is it just me, or does that seem ridiculous? Who surfs, swims, snorkels or sails around 300 feet deep?

Richard.

 

[supergaijin]

It's just you. The 'non diver' watches aren't actually pressure tested- that costs a bunch of money. You pay a bundle for something like the G-shock Frogman which actually has tests to more than the stated depth limits.

Other watches are estimated- some survive, some fail.

 

[shoredivr]

I've written my own product manuals, and had hired tech writers produce manuals for my products. Engineers suck at writing manuals in part for the reason you cited. Also, we tend to assume our audience has a level of knowledge that they may not. On the other hand, frequently tech writers are not sufficiently versed in the operation of the product they're writing about. I think it would be great if tech writers worked with the engineers. Usually project managers don't want to spring for the cost of paying both to do the work at the end of a project.

Hit the nail on the head. It's endemic with product manuals in general and is IMO a flaw
in the system. The extra cost in hiring someone who knows how to write a manual aimed at someone who knows nothing about the product would be balanced out by having happy customers talking about how easy it is to set up the computer.

Jim Lapenta's info on how easy to read and set up the Shearwater Peterel is a great example. My next tech computer will be a Shearwater based partly on this.