Computer Question

[descend]

I'm no expert on general electronic / computer gadgetry, so excuse my ignorance, but: Is there a market out there for a simple, cost effective, rec only LED comp out there? Reason I ask is that a LOT of rec divers have difficulty reading LCD and are interested in the higher end models purely because of the screen.

There definitely is a very new market for that, which is what I think the Deepblu Cosmiq, Watoom Cyano, and the Divememory DM1 are trying to target - with varying success. Seems like a market for startups right now at least.

 

[dmaziuk]

Again, I have no idea, but does it cost a lot more to produce an LED interface? In my head I'm thinking maybe a zoop / puck type product for maybe 50 $ € £ more.

Yes. The regular "7-segment" LCDs are transparent and the segments turn black. DeepBlu uses essentially the same segmented display only it's normally black and its segments turn transparent to let the backlight through. Backlight adds extra drain on the battery but that's about it.

OLED/TFT is a dot-matrix where you need to make characters from dots. That basically requires a video card with the whole 'nother kind of power drain and CPU that drives it, and so on and so forth. To make things worse, ones with smaller dots cost more to make, and there's so much money in cellphones that nobody bothers making them in other sizes. Smart watches are a sizable market and that's how they can source nice screens for Teric and Garmin and those new Korean ones -- you can't even get those in Perdix/OSTC size for any reasonable amount of money.

Or maybe there a commercial reasons why they want push divers to the mid / high end comps

Yeah, like around a thousand reasons every time the cash register goes ka-chunk?

 

[noj3333]

Cost is not an issue, you want AI, you live i Canada, you want simple, straight forward operation...

Shearwater Teric or Perdix AI.

 

[Diving Dubai]

I'm no expert on general electronic / computer gadgetry, so excuse my ignorance, but: Is there a market out there for a simple, cost effective, rec only LED comp out there? Reason I ask is that a LOT of rec divers have difficulty reading LCD and are interested in the higher end models purely because of the screen.

You are starting to see it, although screen technology is always improving. As already stated there is added complexity of needing more power - which means more expensive batteries and then recharge circuits etc. Plus getting people to buy into rechargeable batteries - there was a resistance to them in some quarters until Shearwater brought out the Teric

Suunto with the D5 are moving the feature rich screens down market (even if it is to the top end of mid range price) No one can predict Shearwater, While some (inc myself) would like to see a Perdix size Teric, I guess Shearwater might well put out a mid range machine that allows more people access to their brand

But as I see it, it'll a long way off before this tech it gets to entry level. There are a huge number of divers who are making 10 -20 dives per year or less to whom a Zoop is perfectly satisfactory and does all they need, and with its annual ish battery change its nice and robust too

 

[purbeast]

While I can't really point you in an exact direction (I am newly OW certified and got a Zoop Vyper Novo) I can tell you that I've been watching some of this guys videos on youtube about BCD's and regulators recently and this guy is very knowledgable and came recommended by someone. He also has a video about computers too which is a little over 20 minutes and you may find useful.

 

[seashepherd]

While I can't really point you in an exact direction (I am newly OW certified and got a Zoop Vyper Novo) I can tell you that I've been watching some of this guys videos on youtube about BCD's and regulators recently and this guy is very knowledgable and came recommended by someone. He also has a video about computers too which is a little over 20 minutes and you may find useful.

Thanks, yeah, I watch Alex Pierce too. A fellow Canuck, with a big store in Richmond Hill not too far from where I live. Great You Tube Channel! I’ve seen his video on computers.

 

[GrafCanuck]

Yes I believe Alex was one of the (or the) owners of Scuba2000 in Richmond Hill.
Going back to the original thread, a year ago I was in a somewhat similar decision. I wanted to invest in a dive computer. At the time I was volunteering at one of the dive shops in Toronto. I narrowed it down to the Cressi Giotto, Oceanic Geo2, ScubaPro Aladdin Sport and the basic Zoop Novo. I passed on the Zoop since the last time I rented it on my first night dive it failed when I was down under. This is after a pre-dive test and testing every 5 minutes or so during the dive. Good thing my 2 buddies had a spare, which I knew beforehand. I could have bought any of these DCs for cost plus 20%. What concerned me was a risk of having to upgrade a few years down the road. In addition, I looked at the total cost of ownership for these entry level rac computers. The replaceable battery is in the $8 per range. Some you have to have the LDS replace which is $50 per. Lastly, I perused all of the used entry level rec dcs that were for sale on ScubaBoard over a few months (earlier this year) and not one had sold. I then started reading about Shearwater, a Canadian company no less. A new Shearwater is definitely not in my budget. Did I say I'm frugal. After a month of procrastinating I made up my mind on a used Shearwater Petrel 1 or 2. I posted an ad on ScubaBoard and within a few days I had an opportunity to purchase for used Petrel 2 for $550 CAD. I grabbed it. My first opportunity to dive with it was last month in Bonaire for a week. Wow. Easy to read and easy to use. Super easy to replace the AA battery. I even sent an email to Shearwater about where I could buy an extra battery cap. They sent me one for free without me even asking.

I'm not on Shearwater's payroll in fact most of my gear is ScubaPro. I believe the major scuba manufacturers make good to great product. They have to else they would go out of business fast. If you want to go real cheap look for a used dive computer on here or other online outlets. My bet is that you will outgrow an entry level DC within a year or two. Try and test out any DC before you buy, if you can. Size, screen clarity, ease of use, battery replacement, feel and fit are just a few qualities you should be looking for. My main goal was to buy a DC that will last me for my diving life. I think I've done that unless I win the next big lottery, and then who knows.

Good luck in your search.

 

[Satrekker]

Shearwater Perdix AI. Best I've used hands down. Started with the Galileo Luna, sold it when the Perdix AI came out and have never regretted it.

 

[KenGordon]

So the way I see it, there are three types of dive computers out there.

A) Those that are designed strictly for the recreational diver: Manufacturer has already determined and algorithm and you can not change that either by purpose or by error. For Suunto and Cressi, it will be RGBM (Reduced Gradient Bubble Model) and Hollis DG series has Buhlmann with predetermined gradient factors. These are the simplest, most user friendly computers because they enable the user to "strap in and jump." There is no chance of user error as the only choice you will ever make on them is putting the nitrox percentage. Examples are, Mares Puck, Cressi Leonardo, Hollis DG 02 etc. For a recreational diver, any computer above these may not offer any advantage in the dive profile itself. You may have to justify the value of higher-end computers on totally different criteria such as larger display screen and better cosmetics.

B) Rec-Tech hybrids: These are designed for technical divers who dive mostly recreational dives but will also do occasional decompression dives. Most of the time, these run the Buhlmann algorithm and you can not change that. They do give you the choice of changing gradient factors while staying within the algorithm and you can also switch gases during the dive for decompression. They bombard the user with a much wider range of choices than the the first one. If you are strictly a recreational diver then all these additional choices that you will see concealed within their roll down menu will not be necessary and may also open chances of human error. A friend of mine borrowed a dive computer from his technical diving buddy and this one had some technical diving presets from the original users technical dives. These were detected and fixed but had he continued diving with them, then the dives would be very conservative. Some purely-recreational computers start beeping alarms the moment you cross into NDL. You can not miss those as they will very loudly let you know that they are angry. These intermediate-range computers make different assumptions about the user. The moment you go into decompression, these computers tend to assume that you are deliberately doing a decompression dive on back gas. Instead of yelling warnings, they will very quietly start displaying how much time you need to decompress on back-gas before you exit the water.

I have a friend of mine who exceeded the decompression limit on a computer during her dive. I am not sure which model was it or if it was even a Tech-rec one. I am quoting the story as it has some relevance. She looked at the decompression time she had accumulated and thought that this is how much time she had LEFT at that depth! It took some time for her to understand that instead of the number coming down this number kept rising and that is when she realized that she was already well into decompression. She got seriously bent after the dive and was treated for a hit. Not all of that could be attributed to this reading error though. There were other errors made during that particular dive but when you are stressed out and under narcosis then little things can very easily compound the situation.

Bottom line is that by throwing more options at the user they also create a greater margin for human error. At times, this could be on the conservative side while on other occasions it could be on the risk side of the spectrum. Examples of such computers are Hollis TX-1 and Dive Rite Niteq etc.

C) Dedicated Technical Computers: These are designed primarily for technical divers. They allow the users to change, not just gradient factors but algorithms themselves. Decompression theory is changing and these dive computers allow a highly informed user to accommodate whatever research is being put out there on a constant basis. Not all in the technical diving and decompression community agree on what constitutes a safer dive. Bubble models like those on Suunto start to diverge from Dissolved Gas models like those on Hollis and Dive Rite. One family of computers will start generating stops much deeper as you come up while the other family of computers will get you to the highest, shallowest part of the dive that it can get you to without bending you. After that it will keep you there for a long time. Which of the two is better? These computers allow technical divers to determine who they trust more, how much risk they are taking under which scientific assumption and how they plan on distributing their risk between these two models.

Examples are: Perdix and Petrel etc.

When these mid-to high-end computers end up in the hands of recreational divers, then they are using them to do exactly what a very cheap and user-friendly Mares Puck does. The only difference is that now, it is not as user friendly anymore. When I am changing from Air to Nitrox on my Mares Puck then it is a one button process and you cant go wrong on it. When I am doing exactly that on my Hollis TX-1 then it is a three button process to navigate through the menu, set the gas percentage and then make it your primary gas out of the 6 gas options. Yes I have dived on the wrong gas, I will admit it openly. It was during practice dives so it was a negligible error but it would not have happened on the low end Puck that I also own. The TX-1 will take a few more steps to eventually become a "Mares Puck." I have both the Puck and the TX-1 and if I was diving strictly recreational limits while staying within NDL, you wont see the TX-1 on me.

As human beings we are all wired differently so a lot of it will come down to personal preferences and there is not single correct answer. A lot of times these high end computers are acquired simply because of better display and not much else. If I was starting out in diving then I would purchase an entry level Cressi Leonardo on wrist. While it does not have an LED mini-monitor, it still has a decent and well lit display. The conditions in which this display is unreadable may be the conditions extremely unsuited for a recreational dive. (Zero vis cave? I am not sure.) It doesn't overwhelm the entry level user with a long menu and the only human error it lends itself to is wrong nitrox percentage. As long as you can make sure that your nitrox levels are correct, you can focus on other things.

As for integrated air, I am not an expert on that subject. The technology has gotten more reliable and we are seeing less failures today than a few years ago. Batteries still keep running out in the middle of worst moments. My own training has been either through DIR instructors or DIR minded instructors and air integration was seen as a "failure point." I see my set up through Murphy's Law and ask myself, what are the failure points in this? If anything that can go wrong will go wrong on this dive trip then what is it? Plastic buckles will break so I have steel d-rings, straps will snap from the connecting point so I have a once-piece harness. Mechanical objects are more reliable than electronic ones, specially in salt water so SPG is more reliable than air integrated but exactly how much more reliable? That is still open to debate and you see that debate happening on scubaboard on other discussion threads.

If I was starting out in diving, I would buy a strap and dive Cresse Leonardo, clip a mechanical SPG to read air pressure and jump in. Let others debate whether mechanical SPGs are more reliable than electronic air-integrated ones because by the time they have settled that debate, we will all be diving rebreathers anyway.

Really your categories ought to say marketed as rather than designed as. I have done deco dives on a Zoop, not accidentally staying over, but preplanned dives with significant hanging about. If you are doing back gas deco they are all capable.

The only real difference is support for multiple gases, trimix and CCR.

Does the OP own a drysuit yet? If not spend the money on that and buy the cheapest computer. Being warm is much better value for money.

 

[Diving Dubai]

Value for money is a good point and personal too

What actually separates a high end computer from a low end?

Obviously colour screen
Multiple gas's
AI
Tri Mix and CCR


For the following comparison I've used UK prices because I could find all the models available from one store which gave a comparable baseline (Prices in other regions will differ

Entry Level.
Zoop or Puck £200


Suunto
D5 £595
Eon Core £565
Eon Steel £675
(Transmitter £230 ea for these Suuntos)

Shearwater
Perdix £755
Perdix AI £857
Teric £995
(PPS Transmitter for the shearwaters £170 ea)

Mares
Genius £720

Aqualung
I770R £620

Garmin
Descent £900 (no AI)

Ratio
iX3M GPS £900 (Transmitter £295 ea)

OSTC - Not available in US
OSTC plus £570
OSTC 4 £1083


As you can see its anywhere from £600 - £1000 to get a colour screen. They all basically do the same amongst the other basic functions - and you could strap anyone of them and make any dive to 40m+ inc planned backgas deco, no problem. Yes there will be some differences is conservatism between entry level and higher end - even on the same algorithm.

What has to happen is people should make an informed choice and decide if teh additional features are worth the additional cost to them personally and at that time

I personally advise people not to look too far forward (buying a high end computer because they might go Tec in 2-3 years)
Who knows what models will be out in the future and frankley when you go down the Tec hole, then another £600-900 for a new computer in relation to the other equipment and training costs - is nothing.

FYI I've never once used logic in any of my purchases with dive gear or cars (especially cars) - it's not a method I'd recommend though