Oceanic Geo Air - Dive planning

[shannond100]

Hey guys and gals,

I recently bought myself a new Oceanic Geo Air with integrated air. I like the look of the computer and I like not having another hose to get tangled on when donning my gear on the boat. However, I dive with a university based dive club so the procedures are pretty strict and we must provide NDL time before we get in the water. That being said, it was a good thing I had my old computer on me for my dives yesterday because I couldn't get my NDL to resemble a sensible time.

I go into the dive plan menu - (today it doesn't even have the option for anything below 17.3m)
(I'm in Australia, so all of these are metric)
2.7 - 4:43
3.6 - 2:25
4.6 - 1:25
5.4 - 0:59
6.4 - 0:42
7.3 - 0:32
8.2 - 0:26
9.1 - 0:20
10.0 - 0:17
10.9 - 0:14
11.9 - 0:11
12.8 - 0:09
13.7 - 0:08
14.6 - 0:07
15.5 - 0:07
16.4 - 0:06
17.3 - 0:05

So, what am I missing in my setup that prevents me from planning on the surface?
Setting the computer up from the app seems to apply the same settings to the computer, from what I can see. Planning can only be done on the computer.

Menu

Time:
Pretty generic - time format, date format, alternate location time, dual time and default location.

Gas:
All 3 set up as Air

Alarm:
Audible: ON
Max Depth: 30m
elapsed dive time (min): 60
Dive time remaining (min): 5
Max Nitrogen bar Graph: OFF
Turn Pressure: OFF
End Pressure: 50Bar

Utility:
Units: Metric
Conservative factor: OFF
Deep stop: OFF
Algorithm (NDL Basis): DSAT
Safety Stop: ON
Safety Stop Time(min): 3
Safety Stop depth(m): 5
Dive sample rate: 15secs
Backlight Duration: 5secs
1 Transmitter set up - Air only

I don't want to have to continue to carry two computers all the time - although I understand it is sometimes good to carry a spare as a redundant backup. (yesterday was the perfect example of doing this but I only had it in case I couldn't work something out on the Geo)

Pics of the computer attached and a bonus from yesterday's dive.

 

[inquis]

Does this sound normal?

Only if the planner assumes a clean dive. After a dive to 30 m for the max DSAT-NDL time (20 min), followed by a 16 minute surface interval, the NDL for a second drop to 30 m would be 16 mins. That's a shame if the planner does ignore the current tissue status.

 

[tursiops]

Only if the planner assumes a clean dive. After a dive to 30 m for the max DSAT-NDL time (20 min), followed by a 16 minute surface interval, the NDL for a second drop to 30 m would be 16 mins. That's a shame if the planner does ignore the current tissue status.

The manual says the planner takes residual nitrogen into account.

 

[scubadada]

The manual says the planner takes residual nitrogen into account.

My family has had many Oceanic computers over the years, Pro Plus 2s, VT3, Geo 2s, VT4, all of the NDL planners have worked perfectly.

@fortytwo42

Your computer planner is giving you the correct NDL for a clean dive each time, it is defective. Contact Oceanic and/or where you bought it for a plan to remedy this issue.

 

[fortytwo42]

The manual says the planner takes residual nitrogen into account.

It does, but does it seem to you like it does? The fact that the estimates don't seem to change makes me worried. I have never seen them change, regardless of the previous dive.

Only if the planner assumes a clean dive. After a dive to 30 m for the max DSAT-NDL time (20 min), followed by a 16 minute surface interval, the NDL for a second drop to 30 m would be 16 mins. That's a shame if the planner does ignore the current tissue status.

That's my understanding too. I have reached out to Oceanic (I included a video of the computer planning and the previous dive profile) and am awaiting response.

It's possible that my previous dive was not long enough (3 minutes at 39meters and then up), but it seems suspicious.

I'm going to try it again today and am recording videos of the dive computer planning.

 

[tursiops]

It's possible that my previous dive was not long enough (3 minutes at 39meters and then up)

This is such a short dive there may be no residual nitrogen. The PADI dive tables (also DSAT) give no RNT for a dive less than 5 mins to 40m.

ADDED: This is an error. You are in Pressure Group B after 3 mins to 39m. Which drops to no RNT after 3h48min.

 

[fortytwo42]

I found the bug! And it's a bad one in my opinion.

1) I dived 40 meters again (longer dive this time)
2) I finished the dive, the dive planner worked correctly (showing 10 minutes at 30m in dive planner after 11 minutes surface interval)
3) I downloaded the dive via Bluetooth to my phone
4) "plan Air" was reset now. It shows 20 minutes again. (After 13 minutes surface interval)


Dammit. How am I supposed to trust this computer now:-(


TLDR: downloading the dive via Bluetooth seems to reset either dive planner, or the residual nitrogen info (I have no way of confirming what the computer will show under water. I am assuming that the bug will be present at depth as well)

 

[scubadada]

I found the bug! And it's a bad one in my opinion.

1) I dived 40 meters again
2) I finished the dive, the dive planner worked correctly (showing 10 minutes at 30m in dive planner)
3) I downloaded the dive via Bluetooth to my phone
4) "plan Air" was reset now. It shows 20 minutes again.


Dammit. How am I supposed to trust this computer now:-(

I wonder if this is your computer or a general problem? Are there other divers with a Geo Air who could comment?

Regardless, I would imagine that Oceanic would like to know about this problem. Reset tissues should only be a function used on purpose for something like rental computers.

 

[tursiops]

I found the bug! And it's a bad one in my opinion.

1) I dived 40 meters again (longer dive this time)
2) I finished the dive, the dive planner worked correctly (showing 10 minutes at 30m in dive planner after 11 minutes surface interval)
3) I downloaded the dive via Bluetooth to my phone
4) "plan Air" was reset now. It shows 20 minutes again. (After 13 minutes surface interval)


Dammit. How am I supposed to trust this computer now:-(


TLDR: downloading the dive via Bluetooth seems to reset either dive planner, or the residual nitrogen info (I have no way of confirming what the computer will show under water. I am assuming that the bug will be present at depth as well)

Is it possible there is a setting in the BT downloader that is intended for dive operators to allow the computer to be reset to "clean" for rental purposes? A checkbox? What program are you using to BT-download?

 

[fortytwo42]

I'm using the official software for this computer: diverlog+ from Pelagic. I do not see a setting like this.

 

[fortytwo42]

I have a video of a repro. Interestingly, the DESAT time changed from 18 hours to 1 hour after downloading the dive via Bluetooth.

Video of the whole repro: New video


I contacted Oceanic.