Shearwater fans.....question?

[ajduplessis]

I use VPM-B and match/plan against V-Planner and Baltic. IMO it all about what you prefer wrt deco shape and how you feel getting out the water. Many divers only use Buhlman while other swear by VPM. Experiment and decide what works for you. There is no hard and fast!!

BTW you will now also have a hybrid VPM-B with high GF as option after the unlock.

 

[clownfishsydney]

My wife uses Buhlman with standard GFs.

 

[lindenbruce]

Funny to read that most users who upgraded to VPM are still using the Buhlman. I did the same!
I upgraded to VPM in case students would prefer to use VPM on laptop decompression softwares so that the Shearwater would still have a close deco schedule... and hardly ever used it. Have done a few dives with Predator on Buhlman and Petrel on VPM for comparison purposes.
On top of having a lot more dives on Buhlman and understanding the algorithm better, i feel I can adapt it much more closely and easily to the specific need of a particular dive. GF is also the algorithm used by the onboard computer on my rebreather.

So Geko,
When you did your dives with one computer at one algorithm and the other at another, how did they compare side by side during the dive? it would be interesting to know. Thanks, Bruce

 

[pensacolaracer]

For the record, if I dive the two computers together they match exactly. I would be concerned if they did not.

If it hair lips the pope, one day I am gonna break you of that habit.



Sent from 115 FSW.

 

[Dsix36]

I have been using the GF's and never even considered using the VPM option.

 

[Jim Lapenta]

Have not yet unlocked FPM but do cut back up tables on V planner with conservatism set at +2 and carry a BT as back up.

 

[DA Aquamaster]

I have a pair of Predators and added VPM to one of them just to see how well it worked/compared to the Buhlman profiles.

I found that in general, the VPM-B when set on +2 runs pretty close to the 30/85 GFs on moderate deco dives, with the VPM wanting the first stop deeper, but with the Buhlman Predator wanting a few more minutes at the last stop.

In terms of adaptability, I've found that VPM is a bit of a pita as you can select the conservatism but not really adapt the profile. On the other hand with the Buhlman Predator I can adjust the GFs to adjust the curve for deeper short bottom time deco dives versus shallower but much longer deco dives.

Consequently, I've never upgraded my second Predator and rely on the Buhlman calculations.

 

[ajduplessis]

I have a pair of Predators and added VPM to one of them just to see how well it worked/compared to the Buhlman profiles.

I found that in general, the VPM-B when set on +2 runs pretty close to the 30/85 GFs on moderate deco dives, with the VPM wanting the first stop deeper, but with the Buhlman Predator wanting a few more minutes at the last stop.

In terms of adaptability, I've found that VPM is a bit of a pita as you can select the conservatism but not really adapt the profile. On the other hand with the Buhlman Predator I can adjust the GFs to adjust the curve for deeper short bottom time deco dives versus shallower but much longer deco dives.

Consequently, I've never upgraded my second Predator and rely on the Buhlman calculations.

The nice thing about Shearwater is that the system will do real-time updates to your profile as the dive change, irrespective of algo. Thus there is no need to make any system changes while diving. If you decide to stop deeper/shallower/longer/shorter you just do it. The system will recalc in real-time and adapt you current shape. You can quickly see the new shape during the dive via the on-board planner. No sure why its a PITA???

 

[DA Aquamaster]

The nice thing about Shearwater is that the system will do real-time updates to your profile as the dive change, irrespective of algo. Thus there is no need to make any system changes while diving. If you decide to stop deeper/shallower/longer/shorter you just do it. The system will recalc in real-time and adapt you current shape. You can quickly see the new shape during the dive via the on-board planner. No sure why its a PITA???

First, if you think about the fact that I've been diving with 1 predator running GFs and the other running VPM-B, you'll realize that I've been doing exactly what you're suggesting - adapting it under water. The question is why put yourself in a position to have to do that if there is no upside?

Second, you're preaching to the choir. I like the fact that with the Shearwater I am the final decision maker on whether I extend a stop, etc and can dive it however I want to dive it in the water.

Third, I prefer the Buhlman G/F approach as it lets me tailor the curve prior to the start of the dive for planning purposes with a much greater degree of facility than the limited conservatism settings in VPM-B.

Finally, if Buhlman is the stock algorithm, allows you more flexibility in pre-dive planning and adjustment of the curve - and you will basically ignore/adapt the much less adaptable VPM-B profile during the dive anyway, then why bother with, and pay extra for, VPM-B?

 

[manni-yunk]

I have a pair of Predators and added VPM to one of them just to see how well it worked/compared to the Buhlman profiles.

I found that in general, the VPM-B when set on +2 runs pretty close to the 30/85 GFs on moderate deco dives, with the VPM wanting the first stop deeper, but with the Buhlman Predator wanting a few more minutes at the last stop.

In terms of adaptability, I've found that VPM is a bit of a pita as you can select the conservatism but not really adapt the profile. On the other hand with the Buhlman Predator I can adjust the GFs to adjust the curve for deeper short bottom time deco dives versus shallower but much longer deco dives.

Consequently, I've never upgraded my second Predator and rely on the Buhlman calculations.

Cant you adjust the GF on the VPM-B computer as well?