PSA - Shearwater "Live" Deco & Bailout Plan

[beldridg]

In case divers weren't aware (I wasn't until I recently really started to explore it), Shearwater computers can display a "live" Deco Plan and, if you are on a rebreather, what your Bailout Plan would look like including gas switches, deco stops, AND gas(es) consumed.

AFAICT, this "feature" is not well documented in any of the Shearwater manuals. I recommend playing with it next time you are on a deco stop.

Now, if they would just add a "Bailout TTS" data point that can be easily accessed similar to SurfGF, @+5, etc....

Details of how it works and all the data fields available are posted here:

Shearwater Live Deco Plan, Part II

Background This article is about a “feature” in the Shearwater diver computer that I believe most people are unaware of and that is not really documented in the user manual. It is about…

wreckedinmyrevo.com

- brett

 

[LFMarm]

@Shearwater +1 on the BO TSS measure for the NDL screen

 

[lostsheep]

@Shearwater +1 for the BO TTS

 

[lermontov]

thanks brett - in regard to BO TTS you can get the information by just switching to BO although im not sure if you can then access deco schedule and gas quantities as i havent tried that

 

[Marcozx]

@Shearwater can we also have seperate GF settings for bailout?

Possibly a bailout countdown also, based on a sac setting, bailout GF and the pre defined bailout gas list - with an additional 3 minute warning that your about to exceed the gas available in your bailout plan. After all, we can plan bailouts based on theoretical depths, time...... would be nice for a real time figure

 

[grantctobin]

@Shearwater can we also have seperate GF settings for bailout?

Possibly a bailout countdown also, based on a sac setting, bailout GF and the pre defined bailout gas list - with an additional 3 minute warning that your about to exceed the gas available in your bailout plan. After all, we can plan bailouts based on theoretical depths, time...... would be nice for a real time figure

Is it too hard to switch GFhi once you’ve bailed out?

 

[lermontov]

@Shearwater can we also have seperate GF settings for bailout?

Possibly a bailout countdown also, based on a sac setting, bailout GF and the pre defined bailout gas list - with an additional 3 minute warning that your about to exceed the gas available in your bailout plan. After all, we can plan bailouts based on theoretical depths, time...... would be nice for a real time figure

a BO countdown is already present in a way - TTS on CC mode assuming you know your SAC rate and gas quantities you can easily work out when to start an ascent -it doesnt however allow for a co2 hit which which inevitably mean carrying more gas - if im on a deep diver i carry a back up computer on GF 90 that gives me my "got to get out of here" times

 

[Marcozx]

Is it too hard to switch GFhi once you’ve bailed out?

Depends on the bailout circumstances really, if you need to get up asap then playing with GF is going to take time and stress. The AP inspo has automatic user definable GF for on the loop and another set of GF for bailout. I think its a great idea

 

[LFMarm]

I have been doing some in-the-water testing and there is no easy way of doing this today (hence please @Shearwater consider adding this feature).

The way of doing this today is:

• Dive planning
  
  • Define maximum bottom time (BT_max) by simulating a bail out (BO) on a software (SubSurface for me) while using the GF for BO (GF_BO, for me 70/85)
  • Run a CC profile with the gradient factor used for a regular dive (GF_CC, for me 50/60) while doing the same bottom time as the previous point (BT_max)
  • Check the CC TTS just before the BO (TTS_BO)
• Dive execution (option 1)
  
  • Keep computer on CC and check TTS until it reaches TTS_BO
  • At this point you need to end the dive as you would otherwise require more gas than the BO planned
• Dive execution (option 2)
  • From time to time switch the secondary computer to BO while controller stays on CC
  • Change the GF to the BO ones (GF_BO)
  • Check that the TTS is shorter than the one planned (TTS_BO), otherwise end the dive)
  • Go back to CC
  • Change the GF back to the CC setting (GF_CC)
• Dive execution (desired option)
  
  • Have 2 sets of GF (one for CC and one for BO) that are enabled automatically when switching between the 2 modes
  • Have a parameter that can be shown on screen that represents the current TTS if you would bailout and set the GF to the GF_BO

This last option is the most accurate and conveniente. Option 1 is quite convenient because TTS can be shown all the time and compared to TTS_BO. My only concern is that there may be profiles for which this estimation is not conservative (this is just a fear but have not proved it yet).

 

[rjack321]

Depends on the bailout circumstances really, if you need to get up asap then playing with GF is going to take time and stress. The AP inspo has automatic user definable GF for on the loop and another set of GF for bailout. I think its a great idea

If you have any substantive deco at all, taking 1-2mins to dink around and change the GF is really immaterial. If you don't have much deco in the first place, then it doesn't matter anyway. Although I have no plan or intention of upping my GF high just because I bailed.