COBALT-2 wishlist

[tldavis1]

What a great piece of hardware, with even greater potential.

There is something that would be easy to implement and would make many of us happy, and another thing that would require more thought than I've given it, but might improve safety loads.

EASY:
Add another digit to the Target pO2 setting: 1.45 is becoming a standard, but I can't select it.
It makes a good deal of difference for maximum target depth and desired mix. I find myself using 1.5 instead and then calculating my MOD on my own, keeping track of it away from the computer. Not ideal. I also would like the extra digit in the readout (maybe it's there, don't remember).

Also, I find the gas switching controls to be difficult:

CHALLENGE:
Most of us who are switching gases are doing so during deco or "NDL" ascent and I guess most are relying on a pre-dive plan on a table with set stops. But the Cobalt can't switch until the computer says to go, and if I don't hear the alarm and miss the switch button, it doesn't let me go back and mark my switch on the computer. You should let me pick the switch depth (e.g. 21m to 50%O2), or switch gases on demand. Better yet, notice when I stop using my back gas for more than 20 seconds and switch automagically to the stage gas after an alarm to let me cancel it. And tell me my prior and future pO2 in a Switch Gases? screen to make it clear what I'm about to do to myself.

I just want to say that we are paying attention to all these comments, and appreciate the feedback.
...
Thanks,

Ron

 

[Akimbo]

…Add another digit to the Target pO2 setting: 1.45 is becoming a standard, but I can't select it.
It makes a good deal of difference for maximum target depth and desired mix. I find myself using 1.5 instead and then calculating my MOD on my own, keeping track of it away from the computer. Not ideal. I also would like the extra digit in the readout (maybe it's there, don't remember)...

I don’t think the O2 instruments are accurate enough justify that level of precision. The MOD certainly isn’t that critical. The data supporting PPO2 limits are ultra conservative anyway so 1.5 is nothing to fret about. That’s the trouble with digital instruments. Their display gives people a false sense of precision. You might find this interesting:

http://www.scubaboard.com/forums/ma...y/440726-oxygen-toxicity-limits-symptoms.html

 

[RonR]

What a great piece of hardware, with even greater potential.

There is something that would be easy to implement and would make many of us happy, and another thing that would require more thought than I've given it, but might improve safety loads.

EASY:
Add another digit to the Target pO2 setting: 1.45 is becoming a standard, but I can't select it.
It makes a good deal of difference for maximum target depth and desired mix. I find myself using 1.5 instead and then calculating my MOD on my own, keeping track of it away from the computer. Not ideal. I also would like the extra digit in the readout (maybe it's there, don't remember).

The concept of MOD/ PO2 limits is a pretty fuzzy one, it's definitely not precise enough to justify registering in 100th's of an atmosphere- 1.45 to 1.5 would only be about 5' in depth for a 32% mix. One of the ways we try to keep the Cobalt interface uncluttered is to avoid displaying information that isn't really meaningful, so on PO2 we only show to 10th's. What I would recommend is setting the PO2 alert to the next highest level, and trying to stay just a few feet under. You can use the Gas Mix Edit screen to calculate MOD for any mix- just change the Set PO2 alert field and the MOD will update, so you can easily see what it would be for a range of values.

Also, I find the gas switching controls to be difficult:

CHALLENGE:
Most of us who are switching gases are doing so during deco or "NDL" ascent and I guess most are relying on a pre-dive plan on a table with set stops. But the Cobalt can't switch until the computer says to go, and if I don't hear the alarm and miss the switch button, it doesn't let me go back and mark my switch on the computer. You should let me pick the switch depth (e.g. 21m to 50%O2), or switch gases on demand. Better yet, notice when I stop using my back gas for more than 20 seconds and switch automagically to the stage gas after an alarm to let me cancel it. And tell me my prior and future pO2 in a Switch Gases? screen to make it clear what I'm about to do to myself.

Once you have a gas switch alert set in the Cobalt, you can manually initiate a switch at any time by pressing the UP button- you will get a menu of all gasses for which you are shallower than the MOD, and you can select and confirm a switch just as you do when the automatic reminder comes up. You can go back and forth at will. So long as you have at least one additional gas defined that you are within the operating envelope for, the Cobalt doesn't restrict your gas switching.

In order to switch gases at all, you must have a switch alert defined- we designed the Cobalt's firmware this way to prevent confusion on the part of the large majority of users who don't gas switch during dives. We were concerned- and this was validated during field testing- that users could inadvertently trigger a gas switch menu, and just press a SELECT button to make it go away, thereby switching gases in the computer without intending to. So in order to switch gases you need to intentionally plan a switch depth, and you need to do it for every dive- it will clear between dives. The assumption is that divers who are switching gasses are, or should be, planning things out.

The concept of automatically switching based on gas consumption is an appealing one. I question whether our HP sensor is precise enough to notice a 20 second cessation of gas use from a tank- several minutes, yes. But that would not be very good resolution for gas switch calculations on an ascent- though you could make a case for using that as a backup alert. Someday, maybe, flow sensors could be embedded in regulators.

I like the idea of displaying PO2 in the gas switch menu, provided it doesn't end up being a more confusing display. I will take a look at that.

Ron

 

[Dr. Lecter]

You have made certain design choices that favor the lowest common denominator over flexibility for those that would like it, such as alarms that cannot be silenced and an inability to edit gas mixes during a dive. While this is understandable in terms of many, perhaps most, divers using the Cobalt, it would be nice (especially on a wrist mount version) to see an "Expert Mode" option that would allow us to turn off alarms and access more advanced features during a dive.

If I plan a dive with air and 50%/100% deco mixes, but wind up having to do my deco off a buddy's 40%, the Cobalt as currently configured offers no way to calculate an ascent profile based off the dive data and the new mix. Less dramatically and more common, it offers no help to the diver who jumps in with 36% but forgot to program anything but air. There are great reasons why it's better to default to not giving this level of access during a dive -- but I can't think of any reasons not to have the option to change that.

 

[tldavis1]

The concept of MOD/ PO2 limits is a pretty fuzzy one, it's definitely not precise enough to justify registering in 100th's of an atmosphere- 1.45 to 1.5 would only be about 5' in depth for a 32% mix. One of the ways we try to keep the Cobalt interface uncluttered is to avoid displaying information that isn't really meaningful, so on PO2 we only show to 10th's. What I would recommend is setting the PO2 alert to the next highest level, and trying to stay just a few feet under. You can use the Gas Mix Edit screen to calculate MOD for any mix- just change the Set PO2 alert field and the MOD will update, so you can easily see what it would be for a range of values.


Once you have a gas switch alert set in the Cobalt, you can manually initiate a switch at any time by pressing the UP button- you will get a menu of all gasses for which you are shallower than the MOD, and you can select and confirm a switch just as you do when the automatic reminder comes up. You can go back and forth at will. So long as you have at least one additional gas defined that you are within the operating envelope for, the Cobalt doesn't restrict your gas switching.

In order to switch gases at all, you must have a switch alert defined- we designed the Cobalt's firmware this way to prevent confusion on the part of the large majority of users who don't gas switch during dives. We were concerned- and this was validated during field testing- that users could inadvertently trigger a gas switch menu, and just press a SELECT button to make it go away, thereby switching gases in the computer without intending to. So in order to switch gases you need to intentionally plan a switch depth, and you need to do it for every dive- it will clear between dives. The assumption is that divers who are switching gasses are, or should be, planning things out.

The concept of automatically switching based on gas consumption is an appealing one. I question whether our HP sensor is precise enough to notice a 20 second cessation of gas use from a tank- several minutes, yes. But that would not be very good resolution for gas switch calculations on an ascent- though you could make a case for using that as a backup alert. Someday, maybe, flow sensors could be embedded in regulators.

I like the idea of displaying PO2 in the gas switch menu, provided it doesn't end up being a more confusing display. I will take a look at that.

Ron

Ron I really appreciate your thoughtful response. There are a few things I didn't say that might be helpful as you make design decisions:

1) I have used the Cobalt and attempted to tell it about gas switching a total of 3 times. I have yet to succeed. And I'm a sophisticated user, but a beginner at gas switching. Only 101 dives total after all. These were 2 training dives for Advanced Nitrox (50% O2, up to 15 minutes planned deco), and a deep dive where I carried 40% nitrox for a NDL ascent (and more practice). My instructor tried to disuade me from even having the computer in my kit but I begged; we were doing table-based deco.

In short, it had been a few weeks since I read the manual and I couldn't get it right underwater. Kept getting the compass, but none of the buttons was bringing up the gas switch screen and the one time it came up I guess I didn't acknowledge it twice like it says. I'd like to be able to repair the history in the log afterwards, but that doesn't work either. I read the manual again: Try 4 I'll get it right, I bet. Manual is much clearer than I remembered.

2) pO2 divisions: I understand that the setting of 1.45 ATA compared with 1.4 is exactly the same max depth difference (2 meters) as measuring 27% vs. 28% O2 in the mix, and that it seems pedantic to the designers who want a clean interface. But 2 meters is huge in technical diving. And you already have a decimal place, and you already have pedantic divers, and some who want to plan a specific dive to a specific depth with a specific risk factor ... so please if you can't allow us to input a 1.45 max (as some competitor instruments can), can you at least show it in the pO2 level meter while diving, to minimize additional task loading and maximize information clarity? It is nice to see the pO2 changing with depth at that granularity. I built my own O2 meter, and I have a temperature slope change offset table, to measure pO2 of the mix accurately to within about 0.4%. It might be nice to enter that detail to my Cobalt too, although it would make less difference than the current 4 meter (!) granularity of the pO2 choice. And of course this is overthinking, typical online behavior: I think more than I get to dive, darned it.

As you develop new features for the cobalt-II, I hope you can incorporate them into the original cobalt update firmware and keep your user base on top of the curve. What a great tool!

I still like the thoughts of having the Cobalt notice when you stop breathing the main gas, to remind you to note it (perhaps back-dating the switch, if even on the surface later), and finding out what pO2 you will be moving from and into at a switch, but that might be too busy. I like that you don't present as an option a gas too rich at depth. But some people use different pO2 max during deco... would be a nice option too but again think about clarity and simplicity. One of my dive issues undoubtedly was trying to switch to 50% O2 at 21m at first deco stop when it would have violated my stated max pO2, even though it was in my dive training plan. So many ways to go wrong when old training methods and new limits collide with technology. A flashing yellow warning (but available) choice would have been better than no chance to switch at all. It might be nice to keep our computer informed of contingency gas use even when out of range, or at the beginning of short deep stops. And again, it needs to say (flashing yellow) [EAN50: pO2 1.56 ATA!] at the choice, not just 1.6, and let me choose it for deco.

I still love the Cobalt! Thanks for listening!

 

[RonR]

1) The compass will come up when the SELECT button is pressed, it sounds as if you might be getting unwanted button hits? You do need to confirm the switch, hopefully it will work for you now that you know what to be looking for.


If you go to the System Info screen, and select the Demo button, and run out to the last sample screen by pressing SELECT repeatedly, you will get to a screen where the gas switch can be initiated and carried through. The PO2 will display, and the tank pressure will be greyed out once you are on the alternate mix. Keep pressing BACK to return to normal operation.


2) The fuzziness is in the theory itself, in believing we know what the physiological results or risk factors of PO2 are to that level of precision. We don't. For things like MOD, the individual and day to day variability is so much greater that it probably swamps even displaying to 10th's. I like Erik Baker's comment that all decompression theory is an attempt to "draw a clear, bright line through a fuzzy grey area". That's even more true for MOD limits. The fact that we can display some variables to a high level of precision doesn't mean those figures are significant, and displaying them may contribute to the idea that if one stays within the lines/ rules safety is guaranteed. We are actually pretty tight for space in that part of the dive screen, wanting to keep the tank pressure as big as possible- in psi we need room for four digits. We also want to keep screen business to a minimum. But this is also a philosophical position of not wanting to create a false sense of precision. I appreciate the reasons that instructors emphasize hard rules and rigid procedures, particularly in tech, but in reality a couple of meters in relation to MOD at 32%, or 1 meter at 80%, is just noise. Depth is far more significant in relation to deco/ saturation, for instance, so we display depths to single feet or 10th's of meters- but not to inches or 100th's. I can kind of appreciate wanting to see when you might be approaching a PO2 limit, but really those are very blurry boundaries and a digital instrument makes them seem like hard edges. Have to think about perhaps changing this for a "tech" or "expert" interface option.


As to having a different PO2 limit for deco, that is built into the Cobalt. PO2 limits are set for each individual mix, not globally, so if you want to have a 1.5 or 1.4 for one mix, and 1.6 for deco, that's fine.


We have considered showing all mixes (maybe calling out ones you are too deep for with an alert color or extra warning), and we might do that as we evolve more tech features. Also adding PO2 to the mix list, which I think we can do. Initially, our feeling was that not showing a mix might be the most effective warning that the diver needed to think about what they were doing.


As to doing table based deco, you can use the simulator in the Cobalt to create tables based on its algorithm- there is a button in the simulator to display the deco tables generated. Your current real time saturation (and altitude/ barometric pressure) is used as a starting point, and you can add surface interval to generate tables for starting a dive at any point in the future. It's like a desktop computer program, except it knows where you have been. And of course that's what the Cobalt is doing in real time when you are diving with it.


Thanks for the feedback, that's how we keep evolving this computer.


Ron

---------- Post added January 30th, 2013 at 01:15 PM ----------

You have made certain design choices that favor the lowest common denominator over flexibility for those that would like it, such as alarms that cannot be silenced and an inability to edit gas mixes during a dive. While this is understandable in terms of many, perhaps most, divers using the Cobalt, it would be nice (especially on a wrist mount version) to see an "Expert Mode" option that would allow us to turn off alarms and access more advanced features during a dive.

If I plan a dive with air and 50%/100% deco mixes, but wind up having to do my deco off a buddy's 40%, the Cobalt as currently configured offers no way to calculate an ascent profile based off the dive data and the new mix. Less dramatically and more common, it offers no help to the diver who jumps in with 36% but forgot to program anything but air. There are great reasons why it's better to default to not giving this level of access during a dive -- but I can't think of any reasons not to have the option to change that.

I think you make very good points. Atomic wanted us to simplify our interface for recreational divers, and to lock out inadvertent choices. But I can't see any reason, the way the Cobalt is evolving, to not have an interface choice that would allow a deliberate decision for divers to always enable gas switching, or have more mixes, or to change other options. That's the way we originally designed it, in fact, with multiple modes. I think this will be more of an issue for the wrist mount.

A question- in your example of having to use your buddy's 40% instead of the planned 50%, would it be better to
1) have space for programming in enough mixes that you could have pre programmed not just your mixes, but those of others in your group?
2) have the ability to edit a gas mix while underwater- knowing the interface complexity this would require, and that it would probably mean blocking out current dive data while editing (something we have tried to avoid)?
3) Both?

Appreciate the input.

Ron

 

[Dr. Lecter]

A question- in your example of having to use your buddy's 40% instead of the planned 50%, would it be better to
1) have space for programming in enough mixes that you could have pre programmed not just your mixes, but those of others in your group?
2) have the ability to edit a gas mix while underwater- knowing the interface complexity this would require, and that it would probably mean blocking out current dive data while editing (something we have tried to avoid)?
3) Both?

I think having enough space to add additional mixes would be sufficient if the concerns described under 2) really exist. However, I'm not sure why they should.

Editing a gas mix underwater on a Shearwater, for example, isn't particularly complex from a U/I standpoint: bring up and select Define Gas, bring up and select the Gas you're editing, select and change the relevant %s (O2 and He), and save/exit. Having the Cobalt's 4 button interface, moving around and editing should be even less complex.

I don't completely understand the concern about blocking out current dive data while editing, as it's getting into the software side of things. But I would want to have the current dive data continue running in the background using the existing setting for the gas until and unless edits are saved, at which point the edited mix comes into play. Of course, if you're editing a gas that's not currently selected, then there's no problem. Unless you're saying that the way the software handles things means changing from 40%O2 to 50%O2 on Gas #2 at 90:00 into the dive would cause the data for Gas #2 from 00:00-89:59 in the dive to change, too? That would obviously be... bad.

 

[RonR]

Thanks for the thoughts. There is no software concern, it's display design only. Once you are diving, calculations continue no matter what, and data stored with each sample (about every two seconds) stays as it is, subsequent editing of the mix would not change what was already done. The only concern about blocking dive data is that it's something we try to always keep displaying for the diver- not having a separate compass mode, for instance, but showing the dive data along with. Ditto for gas switching or setting a bearing- we just shuffle things around. That might not be possible with on the fly mix editing (but it might). Probably a minor issue in that editing gas mixes is something that you would be done with fairly quickly. We would have to work out navigation in getting to the editing screen, but once we decide to have an advanced mode we can have more options we probably would not want for a pure recreational system.

Good thoughts.

Ron

 

[Dr. Lecter]

Ah, I see what you're saying. Yes, the current gas switch interface wouldn't really work with that design philosophy, and gas mix setting is a whole different screen. Perhaps the more advanced mode can use less of a 'pop up' interface for gas switch and something more modular in terms of screen space -- e.g., have available mixes displayed as an editable/selectable list in the space currently used by a gas switch prompt and do away with help text explanations for editing in this context. Since the Cobalt ignores pressure data for other than primary mixes, I guess you don't need to be able to define tank settings here. Then the question becomes what button brings up the gas screen, unprompted, during a dive...

 

[tldavis1]

Fantastic now I think I understand everything you're trying to say Ron.
I'd always take extra digits but I understand there's only so much room on the screen.
I was pleasantly surprised with how easy it was to see all the data underwater.

Next all I need is for you all to go diving with me!