Difference between MB levels and Gradient Factors
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I read the HR dependence as an attempt at automatic increase in conservatism (longer deco times) after exerting oneself at depth, though I haven't seen a profile comparison (e.g., with & without HR). However, it's not a stretch to manually decrease GFhigh before (or even during) an especially "active" dive, leading to longer deco times. Extending the final stop is also an option, watching SurfGF drop until you're happy.
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The Human Factors, heart rate, breathing, and skin temperature all decrease the NDL and prolong decompression in an unknown manner, on top of the native algorithm. You can blow off your microbubble selection and the computer will decrease all the way down to MB zero. You can blow off your profile dependent intermediate stop and there is no penalty. However HR or breathing result in an altered decompression algorithm (see below). One would have to decrease the dive time to continue as no stop dive. One would have to satisfy all deco stops or risk going into SOS mode and losing operation as a decompression computer. Altering decompression time could affect gas planning.
From the G2 manual, p45:
2.9.5 Workload At the base of any decompression calculation there is the transport of nitrogen from the lungs to the blood and from there to the tissues during on-gassing, and the same but in reverse during off-gassing. As such, it is obvious that the single most important parameter in a decompression calculation is the rate at which blood travels through the body. During heavy exercise, the total blood flow from the heart can be up to 4 times higher than while at rest. This increase in blood flow is rather unevenly distributed, with some tissues such as the Central Nervous System and the brain being unaffected, while others like the muscles receiving up to 10 times more blood than when at rest. The G2 estimates workload based on heart rate or changes in breathing pattern from the high-pressure transmitter, and the decompression calculation in the ZH-L16 ADT model is changed accordingly. This menu allows you to select the workload base or switch off the workload estimation, in which case your G2 will behave like SCUBAPRO dive computer models without heart rate or air integration. SCUBAPRO recommends using the workload and Heart Rate features on all dives, but especially when making technical dives. When the dive goes as planned there is no effect to the decompression schedule. However, when workload is high more decompression time will be required. Adaptive algorithm additionally incorporates into the calculation the water temperature or skin temperature (only with the patented SCUBAPRO Heart Rate Belt or Digital Heart Rate Monitor) and micro bubble formation.
From the Galileo Sol manual, p38:
If Galileo detects a sufficient increase in workload, no-stop times can suddenly shorten and decompression stops can quickly grow
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Looks like something ChatGPT would spew forth. Loads of words with very little actual detail, i.e. the technical nitty-gritty of the proprietary algorithm (not getting at you @scubadada!)
Couple of other things...
Obviously the HP transmitter only monitors open circuit dives. OC's been replaced by rebreathers for deeper dives, i.e. long deco times, as helium's so expensive. In the CCR world, Shearwater computers dominate as they're used for the controllers and are trusted.
Heart rate will vary a bit in a dive. Am certain that a cage dive would get the adrenaline flowing! For normal open circuit dives, you simply won't be diving for very long if you're working hard: heavy breathing = high gas consumption = shorter dive. Even if a "shock" happened in the middle of a dive such that the adrenaline is injected, that period of high stress won't last long and in any case an experienced diver MUST overcome the issue, especially if there's a significant decompression obligation.
So a dive to, say, 40m/132ft for an hour on 28% would yield just under an hour of decompression on your decompression gasses. You plan for that and carry sufficient gas WITH redundancy AND know your max dive time. How much time would this proprietary algorithm knock off your overall deco time for a calm dive, or how much would it add if it's stressful? Ten seconds? A minute? Five minutes?
Of course an experienced diver would know about tweaking the decompression time if the dive's been stressful, you'd add a few more mins so you surface with a lower surface gradient factor. In my experience, waiting five more minutes seems to equate to around 7% to 10% when the GF-Hi is set to 80% (e.g. another 5 mins would get the SurfGF down to 70ish%). (Yesterday, left the bottom after 56 mins between 57m/190ft and 46m/155ft with SurfGF of 320% and TTS of 83 mins. Spent the last 17 mins watching SurfGF drop from 110% to 80%)
Hmmm, $1300, not air-integrated. Not interested.....even if it does appear to be real!
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