V Planner adjustments?

[stangguy327]

Hey,

When I use my dive computer(elite t3) on a deco dive it gives me a single 10' deco stop, and possibly a 20' stop if I am in deco for a bit longer. But my V Planner gives me several stops starting at 60'.

Both profiles will get me out of deco safely, just differently. Is there a way to adjust V Planner to give me the same plan as my computer? I have poked around and can't find any settings that give only 10' stops. I guess the benefit to this is when I dive 100% o2 as my deco mix, The T3 profile will get me to the bottle faster and out of the water faster than V Planner since I wont have all the other deeper stops to do.

 

[superspeed]

Most likely they use different deco algorithms so they are giving you different profiles. This is something your tech instructor/class should have talked about. You cant change the algorithms V-planner uses but there are other programs you could use for dive planning that you could use that would match your computer closer.

 

[rossh]

Hi,

The V-Planner program generates plans based on the VPM-B model. VPM is a dual phase bubble model. The characteristics include deeper stops as part of the ascent. VPM and similar planning methods are well accepted profile shapes today. You cannot force VPM / V-Planner into making plan profiles per some other model criteria.

Your T3 will use a different model like a simplified derivitive of Buhlman / Haldane that is common in recreational computers. These are typically shallow stop only models.

Regards

 

[rongoodman]

From looking at the web site, it appears that the T3 is using a modified Haldanean model, while V-Planner runs VPM, a bubble, or dual phase, algorithm. VPM will have you stopping deeper to prevent bubble growth, while the Haldanean models ignore bubble growth and try to get you shallow as fast as they can(aka "bend and mend"). Buhlmann is a well-known Haldanean model which people usually modify with gradient factors to force deeper stops, similar to what VPM does. "Deco for Divers" by Mark Powell is a good resource to look at.

(Ross has quicker fingers than I do!)

 

[TSandM]

Another vote for Deco for Divers. If you are doing obligatory decompression dives, you should understand this stuff so that you can make more educated choices about which model you want to follow.

 

[stangguy327]

Thanks a lot for all of the input guys!! I will be picking up a copy of Deco for Divers. Unfortunately my deco instructor didn't go as in depth as I would have liked about the different models. I have been doing as much independent learning as I could ever since my class. I definitely will be using the V Planner profile when doing planned deco dives from this point on. Thanks again.

 

[crls]

I will recommend you to read the following :


If you want another recommendation for reading material, let me know. There're tons


Title: Gelatin, bubbles, and the bends.- VPM
Gelatin, bubbles, and the bends.

Deco Myths - Rossh
Decompression myths and mistakes

Title: Introduction to Technical Diving. Hamilton
Introduction to Technical Diving.