I am cross posting my reply on another thread. Perhaps this will help someone make a more informed decision when buying a new computer. Hopefully, computer manufacturers will provide more disclosure on modifications they are implementing on their decompression algorithms.
" I would be cautious about the Pelagic PZ+ algorithm that's found in several computers like Oceanic. Although Pelagic says it's based on Buhlmann ZHL16c, the PZ+ is most likely a modified version with GFs set by the manufacturer. This means you can't customize GF when using the PZ+ and you really don't know what Modifications or GF settings the PZ+ system is using.
Here's why this is a concern.
Recent scientific studies conducted by the US Navy Experimental Diving Unit (NEDU) and leading decompression scientists have concluded that Deep Stops increases the risk of DCS. This is a major finding since Deep Stops have been the status quo in diving for many years and several computer manufacturers have implemented Deep Stops in their products both as a feature and in the computer's deco algorithm.
In the Technical diving community, the prevailing trend is to move away from deep stops to shallow stops. This is simply done by adjusting the GFLO on our computers. But even that is a moving target as research seems to be validating further moving up to a higher GFLO. What does this mean?
* For those with Shearwater, Nitec, H3, etc., using Buhlmann ZHL16c algorithm WITH user customizable GF, we can easily go with the latest findings and research by simply adjusting the GFLO and GFHI on our computers.
* For those with Suunto, Oceanic, Aqualung, and all other computers with "proprietary" algorithms, you don't really know what your computer is doing. Furthermore, if for example, the latest findings are showing GF 50/70 as the setting to minimize Deco risks, you can't change to that GF on your Oceanic or Aqualung computer with PZ+.
* Yes, I would classify the PZ+ as proprietary because, although it is marketed as "based" on Buhlmann ZHL16c, we don't know, and Pelagic is not saying, what modifications they have made to the Buhlmann algorithm and what GF the computer is using to establish conservatism levels (Shearwater does this in their Rec Mode). And, even if you want to, you can't change the GF on a PZ+ computer system.
Computers are expensive and we want to somehow "future proof" our investment when we buy one. The computer's Deco Algorithm is key. Decompression science is changing and if I may add, quite significantly. Just a few years ago, Deep Stops was in vogue. Today, it's a 180 degree shift away from it. Without knowing what your algo is doing or the ability to change it to conform to new findings, we are rending our computer investment obsolete at best and putting ourselves at risk in the worse case."
" I would be cautious about the Pelagic PZ+ algorithm that's found in several computers like Oceanic. Although Pelagic says it's based on Buhlmann ZHL16c, the PZ+ is most likely a modified version with GFs set by the manufacturer. This means you can't customize GF when using the PZ+ and you really don't know what Modifications or GF settings the PZ+ system is using.
Here's why this is a concern.
Recent scientific studies conducted by the US Navy Experimental Diving Unit (NEDU) and leading decompression scientists have concluded that Deep Stops increases the risk of DCS. This is a major finding since Deep Stops have been the status quo in diving for many years and several computer manufacturers have implemented Deep Stops in their products both as a feature and in the computer's deco algorithm.
In the Technical diving community, the prevailing trend is to move away from deep stops to shallow stops. This is simply done by adjusting the GFLO on our computers. But even that is a moving target as research seems to be validating further moving up to a higher GFLO. What does this mean?
* For those with Shearwater, Nitec, H3, etc., using Buhlmann ZHL16c algorithm WITH user customizable GF, we can easily go with the latest findings and research by simply adjusting the GFLO and GFHI on our computers.
* For those with Suunto, Oceanic, Aqualung, and all other computers with "proprietary" algorithms, you don't really know what your computer is doing. Furthermore, if for example, the latest findings are showing GF 50/70 as the setting to minimize Deco risks, you can't change to that GF on your Oceanic or Aqualung computer with PZ+.
* Yes, I would classify the PZ+ as proprietary because, although it is marketed as "based" on Buhlmann ZHL16c, we don't know, and Pelagic is not saying, what modifications they have made to the Buhlmann algorithm and what GF the computer is using to establish conservatism levels (Shearwater does this in their Rec Mode). And, even if you want to, you can't change the GF on a PZ+ computer system.
Computers are expensive and we want to somehow "future proof" our investment when we buy one. The computer's Deco Algorithm is key. Decompression science is changing and if I may add, quite significantly. Just a few years ago, Deep Stops was in vogue. Today, it's a 180 degree shift away from it. Without knowing what your algo is doing or the ability to change it to conform to new findings, we are rending our computer investment obsolete at best and putting ourselves at risk in the worse case."
