Computer Question

[Chidiver1]

Mares? Never again.

Firstly one of the Mares power supplies exploded.

They continually lost date / time, so you'd be part way through a dive trip and you'd suddenly start logging dives 2 days earlier. Really screwed the logs.

We continually had troubles charging one of them.

The Battery replacements were hideously expensive for what was a $10 18650 battery with a pigtail.

And no real support for any of these issues. When the power supply literally exploded, their sum offer was a replacement. Zero care.

And now the buttons stopped working.

Wow. Sounds bad.

I just got through eyeing the iratio 3m tech GPS. Looks and sounds pretty nice.

I'm liking the gamin except no AI.
The Suunto d5 looks nice, but I don't prefer it as much as the Garmin. Now comes the iratio that I didn't know about. Looks and sounds really nice, but I don't know enough about them yet. 5 year warranty sounds good however.

 

[txaggie08]

The point? Recommending a computer that someone can go from OW to tech without a reinvestment. Add to that a good algorithm, and a great interface, it's a wonderful recommendation for someone looking to invest in quality gear.

I have an "entry level" computer I can sit right next to my shearwater in it's recreational mode, and it requires exactly ZERO more input from me. the menus are more readable, easier to understand the changes your making.

The shearwater is still a two button computer. Put it in rec mode and it's a nice, easy to read, informative computer that just works......and has a battery that doesn't require the LDS to service. I'd ask you an opposite question...... why steer new people away from a computer because it CAN do more if you choose to make it do more.

 

[Neilwood]

What exactly is the point of pushing recreational divers to buy the highest end technical dive computer? Technical diving computers enable divers to make some very serious decompression decisions. They will ask you what type of algorithm you plan on diving? To make that decision you need to know short comings of bubble models and assumptions behind dissolved gas models. Once you have chosen that you would like to dive a particular algorithm, they may ask you what sort of gradient factors you will use? To program those, you need to know what were the short comings in dissolved gas models for which gradient factors were developed and how modern decompression research is making certain gradient factors more favorable over others for certain types of dives. Since technical diving computers throw these decisions at the user, they are also throwing risk and liability at the user. It will be far more difficult to sue Shearwater if you get bent because you were diving a really bizarre gradient factor without even knowing what a gradient factor is.

If you are a new recreational diver, any entry level dive computer is a lot safer device to hold in your hand than these high end Shearwaters. Manufacturer has made certain decisions while knowing very well that the person who will dive with these has no idea how to program all these parameters. My advice is to buy an entry level dive computer and enjoy the experience of the dive, rather than spending all this money to enjoy the experience of the purchase. I totally understand that this advice is in sharp contrast to the consumer culture which pushes the most expensive as the best.

As others have pointed out (@outofofficebrb ), there are not a huge amount of dive computers out there that serve the middle range. You have backlit LCD at one end and LED/OLED at the other with not a lot between them. In poor vis, LED/OLED is streets ahead from a usability viewpoint alone.

WRT to the computers being pushed as "technical", all of the ones that keep getting mentioned such as Perdix/Teric, EON core/Steel, etc all have the ability to use the computers as recreational (with low, medium high or 1-3 etc type conservatism) without having to understand the intricacies of GF. I would venture that all dive computers are intrinsically safe when diving within NDL & within the algorithm parameters (ascent rates etc) but possibly with minutely varying degrees of safety. This is due to the conservatism/ aggresiveness of the algorithm - which any responsible diver should try to understand before buying any computer as that should be part of the buying choice. Any diver purchasing should understand how the longer NDL that a particular algorithm provides in relation to another might not necessarily be the best choice from a risk viewpoint due to age, fitness, repetitive diving etc.

I have no intention of ever doing technical diving but I feel that my Perdix is safer than the Giotto for one main reason - I can see the damn thing without having to use both hands. That alone makes it safer in my eyes as trying to see my depth/NDL etc on the Giotto in poor vis is a two handed job as you need either a torch to light the screen or to operate the backlight (which is not great if you need that other hand for other tasks such as DSMB, holding a line etc)

 

[seashepherd]

As others have pointed out (@outofofficebrb ), there are not a huge amount of dive computers out there that serve the middle range. You have backlit LCD at one end and LED/OLED at the other with not a lot between them. In poor vis, LED/OLED is streets ahead from a usability viewpoint alone.

WRT to the computers being pushed as "technical", all of the ones that keep getting mentioned such as Perdix/Teric, EON core/Steel, etc all have the ability to use the computers as recreational (with low, medium high or 1-3 etc type conservatism) without having to understand the intricacies of GF. I would venture that all dive computers are intrinsically safe when diving within NDL & within the algorithm parameters (ascent rates etc) but possibly with minutely varying degrees of safety. This is due to the conservatism/ aggresiveness of the algorithm - which any responsible diver should try to understand before buying any computer as that should be part of the buying choice. Any diver purchasing should understand how the longer NDL that a particular algorithm provides in relation to another might not necessarily be the best choice from a risk viewpoint due to age, fitness, repetitive diving etc.

I have no intention of ever doing technical diving but I feel that my Perdix is safer than the Giotto for one main reason - I can see the damn thing without having to use both hands. That alone makes it safer in my eyes as trying to see my depth/NDL etc on the Giotto in poor vis is a two handed job as you need either a torch to light the screen or to operate the backlight (which is not great if you need that other hand for other tasks such as DSMB, holding a line etc)[/QUOTE

I agree - As long as the computer has a mode for rec diving, who cares if it can do more? And just because I'm a newbie, I don't feel that should restrict to me to only using computers worthy of my lowly status, haha. My car has a lot of features I don't use as well, but its still nice to drive a good car. Also, having a simple easy to use computer does the opposite of what @CAPTAIN SINBAD says - it isn't an act of consumerism, it will hopefully act seamlessly in the background and let you enjoy the dive rather than straining to see it, constantly hassling with it, having service issues, charging problems etc. However, I'm still not certain what to get, but good advice here, thanks!!

 

[BoltSnap]

I have been using the Ratio iX3M Tech+ computer for almost a year now and I love it. Easy to set up and use. The manufacturer updates the firmware frequently adding more features. Awesome screen with very bright colors I have no problem seeing even on the surface in very bright sun in Libya. The screen can be easily read even when read at an angle. Battery life is excellent (USB rechargeable).

Ratio also has the new iDivecolor watch version that is fantastic also.

In all versions, you can start with their recreational versions and update the software to more advanced versions when you need to in the future and pay the price difference for the software upgrade so you don't have to pay the high price for the top of the line tech. version from the beginning.

 

[CAPTAIN SINBAD]

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.

 

[EFX]

What exactly is the point of pushing recreational divers to buy the highest end technical dive computer? Technical diving computers enable divers to make some very serious decompression decisions. They will ask you what type of algorithm you plan on diving? To make that decision you need to know short comings of bubble models and assumptions behind dissolved gas models. Once you have chosen that you would like to dive a particular algorithm, they may ask you what sort of gradient factors you will use? To program those, you need to know what were the short comings in dissolved gas models for which gradient factors were developed and how modern decompression research is making certain gradient factors more favorable over others for certain types of dives. Since technical diving computers throw these decisions at the user, they are also throwing risk and liability at the user. It will be far more difficult to sue Shearwater if you get bent because you were diving a really bizarre gradient factor without even knowing what a gradient factor is.

If you are a new recreational diver, any entry level dive computer is a lot safer device to hold in your hand than these high end Shearwaters. Manufacturer has made certain decisions while knowing very well that the person who will dive with these has no idea how to program all these parameters. My advice is to buy an entry level dive computer and enjoy the experience of the dive, rather than spending all this money to enjoy the experience of the purchase. I totally understand that this advice is in sharp contrast to the consumer culture which pushes the most expensive as the best.

The point of pushing the OP to the Shearwater Perdix is not for risk but for options and it has all the features the OP wanted: ease of use, utility/functionality, easy viewing in low vis, etc.. Rec users can get into trouble if the computer is set to tech mode. In rec mode all those pesky questions you pose above go away. In rec mode the Perdix will show you the GF's it's using for the low, med, or high conservatism setting. Those GF's are chosen for you in rec mode. How many other rec computers will show you the GF's they are using. You simply must trust that what the computer has preselected for you is correct. If cost was an issue I never would have suggested the Perdix because it does cost more than the entry level computers.

 

[EFX]

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.

It's funny that you mention the Mares Puck because that was my last computer before the Perdix. My experience with it was different than yours. I found the Perdix more user friendly than the Puck. The Perdix has two buttons on either side of the case. In any menu the perdix labels each button with the operation it will perform according to the menu/screen choice chosen. For any choice and either button the button push was the same. The Puck on the other hand has one button that you pushed momentarily to cycle through the menus and screens and then an extended button push to change and then accept that choice. There were no on screen explanations or prompts. If I wanted to change from air to Nx32 do I go to the data or the mode menu? If I went to the wrong menu I had to go all the way around and back to the correct menu. It became a guessing game and kind of a PITA.

 

[Neilwood]

It's funny that you mention the Mares Puck because that was my last computer before the Perdix. However, my experience with it was different than yours. I found the Perdix more user friendly than the Puck. The Perdix has two buttons on either side of the case. In any menu the perdix labels each button with the operation it will perform according to the menu/screen choice chosen. For any choice and either button the button push was the same. The Puck on the other hand has one button that you pushed momentarily to cycle through the menus and screens and then an extended button push to change and then accept that choice. There were no on screen explanations or prompts. If I wanted to change from air to Nx32 do I go to the data or the mode menu? If I went to the wrong menu I had to go all the way around and back to the correct menu. It became a guessing game and kind of a PITA.

My experience with the Giotto (which is a three button computer) against the Perdix is that you had to know how to get an operation done on the Giotto (including what button and whether to press or hold it) as opposed to having the button context displayed in the Perdix. Most of that is down to the large screen area but it sure makes it easier to set things.

 

[Graeme Fraser]

As others have pointed out (@outofofficebrb ), there are not a huge amount of dive computers out there that serve the middle range. You have backlit LCD at one end and LED/OLED at the other with not a lot between them. In poor vis, LED/OLED is streets ahead from a usability viewpoint alone.

WRT to the computers being pushed as "technical", all of the ones that keep getting mentioned such as Perdix/Teric, EON core/Steel, etc all have the ability to use the computers as recreational (with low, medium high or 1-3 etc type conservatism) without having to understand the intricacies of GF. I would venture that all dive computers are intrinsically safe when diving within NDL & within the algorithm parameters (ascent rates etc) but possibly with minutely varying degrees of safety. This is due to the conservatism/ aggresiveness of the algorithm - which any responsible diver should try to understand before buying any computer as that should be part of the buying choice. Any diver purchasing should understand how the longer NDL that a particular algorithm provides in relation to another might not necessarily be the best choice from a risk viewpoint due to age, fitness, repetitive diving etc.

I have no intention of ever doing technical diving but I feel that my Perdix is safer than the Giotto for one main reason - I can see the damn thing without having to use both hands. That alone makes it safer in my eyes as trying to see my depth/NDL etc on the Giotto in poor vis is a two handed job as you need either a torch to light the screen or to operate the backlight (which is not great if you need that other hand for other tasks such as DSMB, holding a line etc)

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.

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