VPM VR3 (Target Release is September 1st, 2005)

On the Inspiration list it was posted that the VPM VR3 is going to be released on September 1st, 2005. The cost of the upgrade will depend upon the age of the VR3 (a higher cost for older models). Some older VR3s require a new board for the VPM upgrade. Rumor has it that the VPM model might be VPM-B.

[jammer]

VPM does that stand for Very Pricey Mod.

VPM stands for Varying Permeability Model:

http://www.decompression.org/maiken/...m_Site_Map.htm

"The Varying Permeability Model (VPM) was developed to model laboratory observations of bubble formation and growth in both inanimate (never been alive) and in vivo (soon dead) systems exposed to pressure. In 1986, this model was applied by researchers at the University of Hawaii to calculate Diving Decompression Tables (Reference 1). Although the original VPM is considered dated by specialists in hyperbaric medicine, the time lag between the formulation and public release of the latest decompression methods has left many divers following ascent schedules that are justified by obsolete Victorian era physical models. Further compounding the problem is the widespread use of commercial decompression software with excessive arbitrary parameters hiding behind siren-song front-ends that allow programmers to dish out crucial physiological advice. Finally, the mathematical and physical bases of the bubble models have kept them inaccessible to all without degrees in physics or math and so, apart from reports filtering back from the front lines, few have understood, seen or used this stuff. So, caveat emptor --and beware too!"

[jpdiver]

I have heard that it will be the V-planner tables that are done by Eric Baker that uses VPM-B/E. I have also heard that it will be a permanent choice between VPM or the current Pro Planner tables the VR3 uses. It will not be selectable prior to a dive. I have used V-Planner with success but they are less conservative than Pro-Planner

[crazyduck]

Chip, Awesome write up!

You are totally right about understanding the mathematics behind the bubble models. While at DEMA I grabbed a book outlining the RGBM bubble formula and it was some serious mathematics. I ended up putting the book back on the shelf eventually, I will need to read it.

I do appricate that Ross is very open about the VPM changes he makes to the models and the way he explains the changes. http://www.hhssoftware.com/v-planner/index.html
model information http://www.hhssoftware.com/v-planner/vpmdetail.html

Chip (or anyone who would like to contribute), I have a friend go is going to be diving Truk Lagoon next May. He is a Divemaster, late 40’s, excellent shape. He presently dives an Oceanic Pro Versa 2.0 and the algorithm for that computer is basically converted PADI tables. I am trying to put a packet together of reading materials for him- any thoughts (outside of ditching that computer?)

Andrew

Here's a little light reading material on Decompression Software. Let me know when you're finished and if you want more. 8)

http://www.decompression.org/maiken/...blications.htm

[Webmaster]

As a programmer I must state that I feel eminently qualified to dispense 'crucial psychological advice'. Especially to the unwashed, misguided user ranks that would otherwise surely go astray.

There is no bug, you don't need to call the helpdesk... (wave of the hand)

Enter credit card # here to purchase upgrade:

[Genesis]

News I had heard was that it WOULD be selectable - even between dives in a series - between VPM and the ZHL algo that the VR3 uses now.

I guess we'll see when its released....I really like my VR3, but VPM in it would be even better.....

[John L.]

I have a couple of copies of V-planner, and I am having trouble trying to run them. I don't think they are compatable with windows. When I try to plan out a dive, it says the depth is too deep for this program. Even if I put 100 feet. Whats out there thats simple, and will give me the ease to cut tables without trouble.

I have also heard that it will be a permanent choice between VPM or the current Pro Planner tables the VR3 uses. It will not be selectable prior to a dive.

Ditto! I heard the options are to stay with the Pro-Planner version, of the VR3, or upgrade it to VPM. It's my understanding each VR3 will not contain both Pro-Planner and VPM, it will only contain one decompression algorithm.