Ranking computer manufacturers?

[reefman]

my vote goes to AERIS AND OR OCEANIC. i have an AERIS AI and its performed magnificantly for the past 3 years(aeris atmos II prior to that) including my recent liveaboard trip(14 days and 54 dives!!!)

reefman
key largo

 

[halocline]

Back to the guy in Dubai that's apparently trying to choose between a suunto, cressi, and tusa computer, if I read his post correctly. My first bit of advice would be to look up the old scubadiving mag article that compares the algorithms on various computers. (Someone can post the link if you can't find it.) This will give you a basic idea about the differences between these computers; personally, I'm not at all familiar with the cressi, but I did really consider getting the tusa IQ700. Another one I looked at was the suunto gekko. (I like big easy to read displays and I don't care about download ability) Eventually I settled on the atmos 2, mostly due to price and the display.

The biggest difference between the various manufacturers' dive computers is the way they compute NDL; and there are striking differences. At times a suunto computer could be in deco obligation while an oceanic might have an NDL of close to an hour. While there is a tendency to assume that more conservative computers are "safer" in fact there is no evidence at all that you are safer from DCS using a conservative computer. There have been lots of threads about this topic; you can search to read about the assorted arguments either for or against using a conservative computer.

Once you decide what kind of algorithm you're comfortable with, it comes down to deciding what features you want, as the various models within a specific manufacturer will use the same algorithm. They almost all do nitrox these days; maybe the biggest decision you'll face is whether to go for air integration or not. There are also many threads on that subject; for me it's not worth the money, especially because I like a wrist computer; that means wireless for AI. It's worth the hundreds in savings to have to look at a SPG!

 

[Web Monkey]

The air integrated computers will do exactly what you want, however there are limits imposed by physics, and these are fixed, regardless of which computer you're diving.

If you're sucking your tank down to the point where the computer thinks that given your current SAC you have enough air to get you back to the surface with 500 PSI, and then your buddy comes over and starts hoovering air, it's entirely possible you will not have enough air to get back to the surface.

It's only a computer. If you want to keep more air in reserve, then plan for it by changing the minimum reserve pressure on the computer. Not sure if the others do this, but you can certainly do it with the SmartCom.

This is no different than planning your dive with tables. If you want to keep a bunch of air in reserve, you have to plan for it.

Whether or not you're diving a computer is irrelevant.

Terry

It sounds to me like they calculate the remaining bottom time based on what is necessary to get *me* to the surface with the desired # of PSI, not to get me *and* my buddy breathing off my octo to the surface with that PSI.

It sounds like it also doesn't take into account that if we are sharing air one or both of us is probably somewhat freaked and breathing faster than I was when the dive was going great.

 

[serrada]

It sounds to me like they calculate the remaining bottom time based on what is necessary to get *me* to the surface with the desired # of PSI, not to get me *and* my buddy breathing off my octo to the surface with that PSI.

It sounds like it also doesn't take into account that if we are sharing air one or both of us is probably somewhat freaked and breathing faster than I was when the dive was going great.

First off: If your sharing air with you buddy, its time to forget about anything but getting yourselves to the surface bc your in trouble.

Second it will account for you and your buddies air use. It's a computer. It doesn't know if you have 12 octos. If the consumption is greater than your remaining air your time left at said depth will be 0:00 Minutes.

 

[djanni]

Please place 1 more vote for the "ProPlusII"

 

[Jason Ooi]

I voted for Sunto

 

[vondo]

First off: If your sharing air with you buddy, its time to forget about anything but getting yourselves to the surface bc your in trouble.

Second it will account for you and your buddies air use. It's a computer. It doesn't know if you have 12 octos. If the consumption is greater than your remaining air your time left at said depth will be 0:00 Minutes.

Sorry, I must not have been very clear. I don't care what it does *after* you start sharing air, what I'm interested in is can the Air-time-remaining be made to reflect how much time do I have to dive and still have enough air to get me and my buddy back to the surface.

Calculating how long you can stay and get back to the boat with 500 psi is kind of worthless. If you are at 30 feet, that and the rock bottom number are pretty much the same. If you are at 130', it's totally different. I realize I could input a different number, but that's not helpful for a multilevel dive. In that case, you don't want to overstay your 100' rock bottom at 100', but if you move up to 60' you gain additional time off the gas you had been saving for an emergency.

All this would be solved if you could input a SAC rate (e.g. 2 cf/m) for the ascent portion of the dive and have the computer calculate the remaining bottom time at the current SAC and the ascent at the elevated SAC. That's what I was trying to figure out if they did.

 

[cerich]

Sorry, I must not have been very clear. I don't care what it does *after* you start sharing air, what I'm interested in is can the Air-time-remaining be made to reflect how much time do I have to dive and still have enough air to get me and my buddy back to the surface.



Calculating how long you can stay and get back to the boat with 500 psi is kind of worthless. If you are at 30 feet, that and the rock bottom number are pretty much the same. If you are at 130', it's totally different. I realize I could input a different number, but that's not helpful for a multilevel dive. In that case, you don't want to overstay your 100' rock bottom at 100', but if you move up to 60' you gain additional time off the gas you had been saving for an emergency.



All this would be solved if you could input a SAC rate (e.g. 2 cf/m) for the ascent portion of the dive and have the computer calculate the remaining bottom time at the current SAC and the ascent at the elevated SAC. That's what I was trying to figure out if they did.

You are suggesting that we program the computer to be inaccurate which would in fact upset the vast majority of divers who do not subscribe to rock bottom planning. in all honesty most that subscribe are DIR divers and at least "profess" they don't dive computers....

That being said there is no question tha RB is a good and valid tool to increase the "margin" in dive planning.

BTW a flat 2 cf/m assent rate sounds good but in a real emergency with anything but two very experienced cool headed divers would be well short of actual sac of two divers on one first stage.

 

[vondo]

I guess I'm saying the option would be nice, so a setting for ascent SCA that is "Auto" which means do as you are doing or a user setting. But, I understand your point. I was more hoping that someone did this, it certainly is not a requirement.