dive computers and reverse profiles

[dmaziuk]

VPM-B +5 (the most conservative setting) gave 5 more deep minutes over ZHL GF 35/82 with the same added deep stops of VPM-B +2.

Except that 35/82 is not a good baseline by today's thinking. Try running VPM against 68/82 instead: Gradient Factors in a Post-Deep Stops World

 

[saxman242]

This isn't the best image as I'm overlaying graphs from two different programs, but here is the plan for 170 ft for 30 minutes on ZHL GF 68/82 and Fused RGBM 2 on 0. 68/82 makes all the stops a few minutes earlier and surfaces 15 minutes sooner.

 

[saxman242]

And ZHL GF 68/82 vs Fused RGBM 2 on setting -1. 68/82 again steps slightly earlier and gets you out of the water 1 minute sooner.

 

[tbone1004]

Disproven? Hardly! Your contention that ZHL produces flatter ascent profiles is hardly worth mentioning, at least for the example profiles I gave above. The VPM +2 profile only calls for an extra 3 minutes at the deep end adding stops at 90 and 100 ft while saving you 9 minutes at the 10 foot stop. Granted, +2 is not very conservative. VPM-B +5 (the most conservative setting) gave 5 more deep minutes over ZHL GF 35/82 with the same added deep stops of VPM-B +2.

what @dmaziuk said. Sure, that's the most conservative VPM gets, but 30/70 is the standard that we used for a long time. Now however, the leading experts are saying that we should be pushing our GF-lo up to something like 80% of GF-hi, so your 5 more deep minutes maxes that GF-lo of 35, that much lower, and with a GF-hi of 80, you're probably going to have a GF-lo of 65 or 70. That's why I said the concept of bubble models have essentially been disproven, the concept that they were founded on has been invalidated by the leading researchers in this field. If a single person alive today that was considered an expert in decompression said there was any validity in them, that would be one thing. The problem is the only person who qualified for that died recently, and he hadn't actually done any meaningful research on the subject in close to 40 years

 

[pauldw]

And ZHL GF 68/82 vs Fused RGBM 2 on setting -1. 68/82 again steps slightly earlier and gets you out of the water 1 minute sooner.

So Fused 2 is better for people with prostate problems?

 

[saxman242]

So Fused 2 is better for people with prostate problems?

Hey, it gives you one more minute of time to pee in the ocean. That's gotta be worth something.

 

[dmaziuk]

And ZHL GF 68/82 vs Fused RGBM 2 on setting -1. 68/82 again steps slightly earlier and gets you out of the water 1 minute sooner.

Heh. Can you overlay 10/100 to see how it matches up with their original Fused RGBM?

 

[dmaziuk]

So Fused 2 is better for people with prostate problems?

You gotta be getting a bit chilly after 1 hour 55 minutes in the water. So, add pneumonia and by extension COVID-19. Very apropos.

 

[pauldw]

Hey, it gives you one more minute of time to pee in the ocean. That's gotta be worth something.

Maybe that extra pressure helps push things through the pee tube.

 

[saxman242]

Heh. Can you overlay 10/100 to see how it matches up with their original Fused RGBM?

Much bigger difference here