Question about deco software

[MechDiver]

I tried the VPM for palm and hated the UI. You create a "settings file" using a certain syntax and then run it through the software to spit out the dive plan. No thanks, I like the easily tweakable almost spreadsheet-like interface of Dplan, Jplan, Decoplanner, etc. much better.

PalmVPM is really alot like V-Planner. You set the defaults (settings file), then enter the depth, gas, deco gas and time and the Palm gives you the profile. I don't see any problem changing parameters if needed. And it IS VPM. And free.

MD

 

[chrisch]

By a weird coincidence I have just been given an old Palm for free and the only possible use I could think of was the free V Planner. The software is a bit clunky as mentioned because the interface is text. However, I thought it was a great thing as the Palm is easy to carry on a boat or when travelling. The full version on a laptop is better for sure, but then you have to lug a laptop around.
I have also tried to run the Windows CE V Planner on a sub-notebook but cannot get it to run. This would seem like a good compromise if you can be bothered....

The V Planner deco model is pretty much the best going as far as I can see - whatever platform you run on...

Chris

 

[matt_unique]

Thanks for the replies.The consensus certainly supports VPlanner.

I had my TDI instructor run the exact same sample numbers I plugged into VPlanner on his copy of GUE. It was for a dive to 125' for 30 min using 28%N for back gas and 36%N for deco gas.

>>Here is what GUE would have done:
125/30

110- 1minute (switch to 36%)
30-1 min.
20 - 17 min.s

GUE puts in the deep stop.<<

VPlanner suggests the first stop at 50'. The total deco time from the GUE software is 19 minutes. The total time from VPlanner is 26 minutes and 30 seconds. (30 seconds at 50' switch to deco gas, 2min at 40', 4 min at 30', 20min at 20')

In your opinion, what is safer? Shorter deco but throw in a deep stop or more deco time but first stop is shallower? My instructor felt a deeper stop is important but both would be "safe".

Thanks

--Matt

 

[Genesis]

Personally, I feel much better post-dive if I stop deep and once I begin that process continue to do a deco-like ascent, making stops every 10' up once past the offgassing floor.

Coming up shallow and staying longer forces larger gradients. I don't like that model.

 

[MechDiver]

Thanks for the replies.The consensus certainly supports VPlanner.

I had my TDI instructor run the exact same sample numbers I plugged into VPlanner on his copy of GUE. It was for a dive to 125' for 30 min using 28%N for back gas and 36%N for deco gas.
Thanks
--Matt

There are quite a few settings and switches in VPlanner that need to be looked at/adjusted to fit the dives and diving style. Deep stops, IIRC, is a switch that can be checked/unchecked.

Also, 36% is a rather non-useful deco gas. I would use 50% for the dive you outlined.

MD

 

[O-ring]

There are quite a few settings and switches in VPlanner that need to be looked at/adjusted to fit the dives and diving style. Deep stops, IIRC, is a switch that can be checked/unchecked.

Also, 36% is a rather non-useful deco gas. I would use 50% for the dive you outlined.

MD

MD is right..the conservatism setting has a lot to do with your profile as well, but those decisions should only be made by you, IMHO.

 

[matt_unique]

There are quite a few settings and switches in VPlanner that need to be looked at/adjusted to fit the dives and diving style. Deep stops, IIRC, is a switch that can be checked/unchecked.

Also, 36% is a rather non-useful deco gas. I would use 50% for the dive you outlined.

MD

I omitted all the settings I of course have to place in either software package to condense my posting. (SAC rates, ascent rates, decent rates, time for gas switching, etc., etc., etc.) I was trying to determine what software would offer the safest/most conversative model for deco diving. Basically to see if VPlanner was a good tool to use or if the costly programs are worth the money.

Thanks

 

[Genesis]

MD is right..the conservatism setting has a lot to do with your profile as well, but those decisions should only be made by you, IMHO.

Yep...

My usual "light deco" dives (which is what I mostly do around here when I'm deco diving) have a runtime of about an hour, end-to-end, and the only deco gas I usually sling is a bottle of 50.

There's plenty of argument between the 50 and 100% crowd; my view is that the 50% gets me on the higher PO2 gradient sooner, and therefore if I am forced out of the water before my obligation is completed for some reason I have gotten SOME decompression benefit from the better oxygen window, and if I take a hit as a consequence it might be less severe.

If I'm doing that dive without a "unified team" (and I usually am) then I also insure that my schedule can be decoed out on backgas if I have a "broken" deco bottle.

I typically dive +2 conservatism on Vplanner with deep stops enabled, 2 minutes at gas switches, 20' deep on, window effect on and the last stop at 20'. The latter setting is to keep surface surge from becoming a pain in the butt during the last, and longest, stop, as all these are salt water dives in the ocean.

A typical dive schedules out like this:

Decompression model: VPM-B

DIVE PLAN
Surface interval = 2 day 0 hr 0 min.
Elevation = 0ft
Conservatism = + 2

Dec to 140ft (2) on Nitrox 27.0, 50ft/min descent.
Level 140ft 27:12 (30) on Nitrox 27.0, 1.41 ppO2, 127ft ead
Asc to 100ft (31) on Nitrox 27.0, -30ft/min ascent.
Asc to 70ft (32) on Nitrox 27.0, -30ft/min ascent.
Stop at 70ft 1:40 (34) on Nitrox 50.0, 1.56 ppO2, 32ft ead
Stop at 50ft 0:40 (35) on Nitrox 50.0, 1.26 ppO2, 20ft ead
Stop at 40ft 3:00 (38) on Nitrox 50.0, 1.10 ppO2, 13ft ead
Stop at 30ft 4:00 (42) on Nitrox 50.0, 0.95 ppO2, 7ft ead
Stop at 20ft 19:00 (61) on Nitrox 50.0, 0.80 ppO2, 1ft ead
Asc to sfc. (61) on Nitrox 50.0, -30ft/min ascent.

Off gassing starts at 91.3ft

OTU's this dive: 75
CNS Total: 29.2%

128.7 cu ft Nitrox 27.0
28.4 cu ft Nitrox 50.0
157.1 cu ft TOTAL


DIVE PLAN COMPLETE

-- lost gas -->

OK 50

(30) (30)
70 1 (34)
60 1 (34)
50 0 (35) 3 (37)
40 3 (38) 4 (41)
30 4 (42) 6 (47)
20 19 (61) 36 (83)

I'd do that dive would be done on double HP100s. The double 72s have no margin on thirds for a failure on the assumptions I use for RMVs (0.8 working, 0.5 deco), both of which are intentionally a good bit above my usual actual RMVs. I can deco out on backgas, but cannot support both myself AND another diver doing so - if I'm doing this as a unified team the assumption being made is that if one of us breaks a deco bottle the other's will be ok, and once their deco is complete they can switch back to the backgas (and possibly even let the other diver have the remainder of their deco bottle to enhance their safety) while they complete the lost gas hang.

 

[O-ring]

I agree with the G-man on those profiles. We do a LOT of dives in the 110-140' range with only EAN50 and a lot of hourish runtimes.

On that dive, I would cut that a bit shorter, but to each his own!

 

[Genesis]

I don't mind the extra few minutes.

Diving nominal as opposed to +2 only cuts three minutes off the runtime.