Question Shearwater Teric (GF40/85) goes into DECO on first dive (max depth 25.9m, avg depth 17.6, duration 48mins)

[scubadada]

Thank you all for your response and sharing. I’m really thankful for this forum and for everyone’s helpful replies and advice.

I have another question, with me ending the dive with Surface GF of 84%. Would it be safe for me to dive again? If yes after a surface interval of how long.

Thank you all in advance.

Sure you can dive. Use the NDL planner to see how long your next dive can be after your SI

 

[Divedeeplastlong]

Understood on tending to your wife. The dive guide thing is an irritation of mine. Never JUST follow the dive guide. While they may be responsible for leading the dive, it's the individual diver who should be responsible. After all, the diver will have the consequences should something go wrong.

Unlike your Suunto, the Shearwater won't lock you out. That means, that it will continue to track nitrogen loading on future dives based on your past dives. I'm not a Dr. so I'm not going to make any suggestions regarding the safety of the dive. No symptoms definitely is in favor of you being fine.

If you do decide to dive, then your Teric will continue to provide advice. As long as you follow it, and pay attention to how you are feeling you should be fine.

One additional information point. Look at the tissue loading graph on the Teric. It shows what it expects the various tissue compartments saturation to be currently. If the slower tissues are highly saturated, this might be more of a concern. Also, use the planning function to make sure the upcoming planned dives are doable.

Understood, from my next dive onwards, I won’t just follow the dive guide and listen to my dive computer.

As for the tissue loading graph, the data have been cleared due to me updating the the firmware of the teric at the end of the day (as I assume the teric was malfunctioning and further assumed that updating the firmware will resolve any bug - not knowing that by updating the firmware would clear the tissue loading).

Could you be so kind to share briefly or post a link on some explanation on how to interpret the tissue graph on the teric and which is the chart for slower tissue?

I managed to find 1 sample tissue chart but it doesn’t explain much.

Thank you so much in advance.

 

[Divedeeplastlong]

Sure you can dive. Use the NDL planner to see how long your next dive can be after your SI

Thanks again for your prompt reply and advice. Btw, I don’t see a dive planner on my teric. Do I use an online dive planner instead?

 

[scubadada]

Thanks again for your prompt reply and advice. Btw, I don’t see a dive planner on my teric. Do I use an online dive planner instead?

Dive-Dive Tools-NDL Plan

p 45

 

[dflaher]

You're getting some good advice here, @Divedeeplastlong . So am I . Another tool which can be helpful while on a dive is to monitor your GF99 and SurfGF real-time. The Shearwater computers allow you to do this. Here is a helpful article about this:

Shearwater Dive Computer Settings: Become A GF Power User!

I will let others answer your tissue graph question, but I believe the faster tissue compartments are on the top and the slowest are on the bottom. There's a reason the medium tissues have the higher GFs but I don't fully understand why at this point.

 

[Blackcrusader]

Hi all, my Shearwater Teric goes into DECO on first dive (max depth 25.9m, avg depth 17.6, duration 48mins). Isit acting normal?

OK I have come across divers who buy a DC then do not know how it works or what settings are being used. It is good you posted your thread hope we can all help you.

The malfunction is the user not the DC and the operator not knowing how it works. You need to study up on your GF Settings Surf GF and other functions Shearwater has. Download the user manual and read it several times. Look on SB for discussions on Gradient Factors and Surf GF.

I was diving in June and a woman complained to her guide and my guide that I must have gone into Deco as her Peregrine was showing 1 minute to NDL and I was deeper and stayed longer. When I asked her what GF settings her Shearwater was on she gave me that blank look of this does not compute what settings? After showing her settings and explaining why I have longer NDL times she asked would I change her settings. I said to her its your DC, follow what I say and let her change the settings herself. She changed to the 45/95 setting as she wanted longer NDL times not just on 21% but also on nitrox.

My Shearwater is set at GF 45/95 and hers was on default with a more conservative setting. I showed her on her Peregrine where to change settings. She had no clue but had owned the Peregrine for some time.

Here is a log of mine on 21% air. Second dive of the morning. 29th of 30 dives in 10 days. At the end of the dive I saw a nice frog fish so I looked at my DC. I only needed to descend a couple of meters but I pushed to zero NDL. I wanted to squeeze in some photos and I did. I am deco trained. The average depth on this dive was 15.7m

My guide and another diver with no DC was at less than 10m depth because my guides Suunto cannot match my Shearwater for NDL.
This is fine, I do not rely on a guide for my dives and he did 27 dives with me took one day off.

Scubaboard is a great resource for learning from the masters here. I am not a master just a recreational diver who understand what my Perdix is telling me. I spent many hours learning about Gradient Factors, Surf GF, GF99, using my Perdix to plan dives.

Another good thing is that if you noted your starting and ending pressure, know you tank size, the software will calculate your RMV or Sac rate for you. Then you can average your gas consumption over say a dive trip or for all your dives.

 

[dmaziuk]

... There's a reason the medium tissues have the higher GFs but I don't fully understand why at this point.

Fast tissues off-gas fast (as in: on ascent if you stick to safe ascent rate) and slow tissues don't really on-gas much on no-stop dives. So that leaves us with the medium ones.

 

[Blackcrusader]

I have very limited knowledge on GF and what GF I should set.
Should I change my teric GF to 70/85 to match my wife’s AWU so we both will have similar NDL/DECO?
Thank you all so much.

Thanks to everyone’s reply. To assure me that my teric is working fine and safe to continue diving with.

It really does not matter what your settings are. Both divers need to monitor their own dives. If one diver has longer NDL times due to settings they can simply stay with the other diver who has less NDL time rather than trying to match settings on different brands of DC's.

I have a buddy who had Oceanic DC's for many years. He got a Perdix and and have the same firmware version and settings. It means when we dive we do so without regard to say a PADI guide using a Suunto or other DC. We let guides find some critters we may want to see but we control our own dives.

Also you can have an NDL warning so you can set the warning to come on at say 4 minutes to NDL.
I have mine turned off now as I pay attention to my NDL always.

Go to the 1 minute mark on this video. You can see the NDL is in a warning colour as I had set it for that.

 

[Blackcrusader]

Hi, I was tending to my wife (new diver) so I didn’t really focus on my dive computer. As for the ascending and descending, we followed our dive guide.

You need to learn not to follow a guide who may have a different DC / settings. You have to follow your own dive computer.
Also at anytime you can look at your DC and say hey, I have 5 minutes to NDL but I will ascend to where I get 10 mins NDL.
I know some dive ops ask divers to ascend when they get to 5 minutes of NDL so divers who might otherwise not pay attention to their DC's do not go into deco and not realize they had done so.

 

[Blackcrusader]

Thank you all for your response and sharing. I’m really thankful for this forum and for everyone’s helpful replies and advice.

I have another question, with me ending the dive with Surface GF of 84%. Would it be safe for me to dive again? If yes after a surface interval of how long.

Thank you all in advance.

OK there is this. A diver can call a dive or not go on a dive anytime they feel there is a risk they do not want to undertake.

So you missed a deco obligation. Yes maybe you do not feel any effects. Safety wise I would say take a day off and then be certain you are clear. Others may look at your log and say yes if your next dive you had say an 18 hour surface interval you are fine to dive again.