Scubapro Galileo 2?

[scubadada]

I suspect the HR and workload effects on the algorithm are based on some scientific data as they’ve been using this for several years now with the Galileo, and they could probably supply you with the study if you ask the right person. But in any case I like the idea of monitoring my HR while I dive. I do so when I exercise in other sports and it’s useful feedback and is being used by active people more and more.

However, unlike many other activities, scuba is not an aerobic sport

 

[tridacna]

I was one of the very early Galileo adopters.

Years ago I was using it on a Jersey wreck dive with the chest strap. It was cold and deep and somehow the computer contrived that my heart rate had gone from 82 to 240 bpm and locked up the computer pronto. Faulty chest strap perhaps? But a lock up? I’m sure that they fixed that “feature” by now but I never used the chest strap again. Worthless POS feature with minimal upside.

 

[dmaziuk]

Look at the bright side: they have not added the automagic defibrillator. Yet.

 

[scubadada]

Look at the bright side: they have not added the automagic defibrillator. Yet.

That might not be a good thing combined with with a heart rate chest strap malfunction like @tridacna reported. A rate of 240 just might be read as ventricular tachycardia

 

[guyharrisonphoto]

In addition, set the microbubble level at zero, turn off PDIS, and you should be diving the native algorithm, Buhlmann ZH-L16 ADT. You might also have to set the air consumption setting to -12.

The G2 was tested as part of the 2017 ScubaLab dive computer review. They state they test at the "most liberal settings". The G2 came in at the conservative end of the spectrum, most conservative at some timepoints. The data from the 4 simulated hyperbaric chamber dives can be downloaded as an Excel spreadsheet from the Scuba Diving Magazine website 11 New Dive Computers Tested By ScubaLab In 2017

I can't make heads or tails of what this chart is showing. Also, the bottom times seem completely wrong (100 feet for 55 mins, on air??). What does "arrive" and "depart" mean for the different depths? Were there stops being made at each depth instead of a regular ascent? Can someone help me figure this out?

 

[scubadada]

I can't make heads or tails of what this chart is showing. Also, the bottom times seem completely wrong (100 feet for 55 mins, on air??). What does "arrive" and "depart" mean for the different depths? Were there stops being made at each depth instead of a regular ascent? Can someone help me figure this out?

Hi @guyharrisonphoto

Sorry for the confusion, I have been following this chamber testing since at least 2014 and am reasonably familiar with it. You are correct, all of these dives are multilevel dives. The 4 dives are described in more detail and the dive profiles are included in the 2014 publication http://ads.bonniercorp.com/scuba/PDF/ScubaLab-Computer-Test-September-2014-data.pdf They did not always report arrival and departure, yes that is arrival and departure from each depth. I believe there was a minor modification made in dive #1, but I do not remember exactly what or when it was. @stuartv has commented on it previously, perhaps he could comment. Regardless, this is hyperbaric chamber simulation of 4 dives done in a single day with reasonable SIs. It is some of the only data available to show how various computers/deco algorithms are affected by repetitive dives. All the computers were treated in exactly the same way, their respective NDLs can be compared within the limitations of the 4 dives chosen by ScubaLab.

 

[guyharrisonphoto]

Thanks very much for that link!

OK, think I am getting it, but still some questions. I assume the charts are showing the NDL when "arriving" at depth and when "departing" the depth after the designated dive time. But, how come the NDLs only change a couple of minutes, when the total dive time should have been the reduction? Just look at dive 1 and take the Shearwater Perdix AI. "Arrive" at 100' with "14" NDL, spend 8 minutes dive time, but "depart" with 10 mins NDL? Why is it not 6 mins which should have been by using 8 of the 14 minutes. Similar for all the depths.

I think I am still missing something?

 

[scubadada]

Thanks very much for that link!

OK, think I am getting it, but still some questions. I assume the charts are showing the NDL when "arriving" at depth and when "departing" the depth after the designated dive time. But, how come the NDLs only change a couple of minutes, when the total dive time should have been the reduction? Just look at dive 1 and take the Shearwater Perdix AI. "Arrive" at 100' with "14" NDL, spend 8 minutes dive time, but "depart" with 10 mins NDL? Why is it not 6 mins which should have been by using 8 of the 14 minutes. Similar for all the depths.

I think I am still missing something?

Sorry, I cannot help you with how the algorithms perform

 

[dmaziuk]

I think I am still missing something?

Nope: the "tests" are garbage.

Somebody pulled some dive profiles out of some orifice for no apparent reason other than maybe they were uncomfortable up there. They used them to "measure" something they forgot to actually define as any kind of measurable quantity. Without bothering to specify what they're measuring with or against. And went downhill from there. You're not missing anything.

 

[guyharrisonphoto]

I hate to think that "garbage tests" are the answer, as they were trying to generate useful information for comparison (I don't even mind the odd dive profiles, as all computers were treated the same), but something is certainly missing or unexplained about this.

There is just no way to justify what is reported with reality. An NDL of 14 upon arriving at 100 feet will be an NDL of 6 after 8 minutes. That is just a fact--it is a simple countdown. There is no "quirk" in any algorithm that magically adds time. The Shearwater was just a example but all computers show the same issue at all depths in all the dives.

There has to be some further explanation of what the numbers mean, unless the actual test was screwed up in its execution.