Teric not Accepted as Primary Dive Computer?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Given the text quoted immediately above from SW's website is older than the Teric, and the Teric doesn't have the ability to change GFs on the fly but also introduced SurfGF, then I'm curious about @Shearwater's thinking on this (using GF99, SurfGF versus modifying GFs on the fly) and if they'd like to chime in post returning from DEMA?

This post is the closest thing you can already find in their website. Surface GF and Other Teric Musings - Shearwater Research
SurfGF has been available to Petrel and Perdix only for about a season. You can get the same results with GF99/SurfGF or changing your GFHi. The fact that changing GFHi underwater was left out from Teric gives you an idea what Shearwater seems to prefer.
 
Thank you both for the informative discussion.

Given the text quoted immediately above from SW's website is older than the Teric, and the Teric doesn't have the ability to change GFs on the fly but also introduced SurfGF, then I'm curious about @Shearwater's thinking on this (using GF99, SurfGF versus modifying GFs on the fly) and if they'd like to chime in post returning from DEMA?

Good point! Hopefully @Shearwater will weigh in. I don't mean to speak for them, but I'm pretty sure that if an older portion of their web site had a statement that they now felt was obsolete given their current firmware, they would simply change it.

To summarize, I think that we are talking about three ways of modifying your decompression profile on the fly, either to get you out of the water sooner (if there are operational reasons to do so like lost gas or a dry suit flood), OR to keep you in the water longer and give you give you a bigger decompression safety margin (if you thought that you had greater than planned stress, like working harder):

1) Changing GFHigh at depth. This changes the entire ascent schedule, giving you a series of different stops that you can then follow as usual.

2) Picking a constant maximum allowable overpressure, watching your GF99 during ascent, and not letting it get over that number. When you surface from the last stop, you can just watch GFSurf and leave that stop when it is below your desired overpressure instead of watching GF99 as you ascend, since it will have the same effect.

3) Ascending according to your profile generated by your original GFlo and GFHi, but then watching your SurfGF on the last stop and surfacing when it is higher or lower than your original GFHi.

You couldn't do #3 until the new SurfGF firmware upgrade was available, and the advantages of that are described in this recent article. And I don't think that it would make sense to do #2 if you wanted to INCREASE your decompression margin, it's primarily a way of making an ascent that gets you out of the water faster with fewer deep stops and less gas usage. In other words, more for emergencies.
 
There is an interesting change related to this discussion in Teric release notes for firmware version 16.
This should be coming to Petrel/Perdix soon too.
I had to remove SurfGF from my main screen because it displayed in red while diving according to the plan. This annoyed me and my buddies.
With this new color coding, it is theoretically possible to do a meaningful emergency ascent by only looking at SurfGF display. First keeping it yellow (staying under GF 100%) and then doing a shallow stop or stops until SurfGF reaches your personal favorite value for acceptable risk.

upload_2019-11-17_14-52-2.png
 
Hi all,

He teaches a lot of different methods, very few are engraved in stone this is the only way type teaching, take it or leave it - the sun will still come up tomorrow.

Chatterton holds some strong opinions. Frankly, he also has creds to hold therm. I don't have to agree with him. But, I won't simply dismiss his opinions out of hand. Rather, I would want to better understand WHY he holds them.

He's a great teacher, and while he might not spend time on the fundamentals of trim, etc.. that you can get from many other excellent instructors, he brings to the class experience, stories (and entertainment if you are into the history of diving) that you simply can't get anywhere else.

A reminder for the readers, what has been posted here lately by people who took a class from Chatterton seemed pretty unanimous that they all liked it and felt that they got a lot from it.

Disclaimer: I am not a tech diver...I do have a tech 40 cert card...I am still not a tech diver.

The posts I have quoted above really set the proper tone. Thanks to @drainaps for starting this thread (Teric not Accepted as Primary Dive Computer?)

Compared to JC, 98% (more like 99.8%) of us on Scubaboard are keyboard warriors. He was a professional commercial diver for decades. He survived where others died. He had the wherewithal to rescue people who were seriously bent and not get bent himself; he tried to rescue these people while on the same dive in the same vicinity. Not as a rescue or recovery diver, as a fellow diver.

If Richie Kohler and/or JC told me to follow some technique or dive plan and any one of you objected, I would listen to Richie or John, and not you. While @Akimbo, @Wookie, @rsingler or @doctormike, et allia, are in same league, even though they may be from different niches, I would still follow Richie and John's advice. I would definitely be saying to myself: Oh f**k, oh s**t, whose advice do I follow?

If Bruce, Lynn, or Pete told me not to follow John or Richie's advice, I would thumb the dive (only because I have a personal relationship with these people).

It is his class. It is his topic. If you don't like the syllabus, find someone who teaches what you want to be taught. Decades of real-life experience matters.

As far as other PDCs v. Shearwater: I am a fan-boy of Shearwater. I don't have any experience with Eon or other comparable computers. I bet if I used one of the other PDCs, I would sing their praises also. It is just a computer; however, the principals of Shearwater have sold themselves to me in person. They are highly ethical people; they hooked me.

cheers,
m
 
I would definitely be saying to myself: Oh f**k, oh s**t, whose advice do I follow?

Hopefully you gain enough understanding from justifications provided with any advice you get to make your own informed decision for your situation -- regardless of the subject. Decisions are rarely binary. The best option is usually the one with the least onerous compromises.

Want a setting so you NEVER get bent? Set the depth alarm to 15'/5M. It gets a lot murkier after that. :)
 
Hopefully you gain enough understanding from justifications provided with any advice you get to make your own informed decision for your situation -- regardless of the subject. Decisions are rarely binary. The best option is usually the one with the least onerous compromises.

Want a setting so you NEVER get bent? Set the depth alarm to 15'/5M. It gets a lot murkier after that. :)
:cheers:
 
Hi all,









Disclaimer: I am not a tech diver...I do have a tech 40 cert card...I am still not a tech diver.

The posts I have quoted above really set the proper tone. Thanks to @drainaps for starting this thread (Teric not Accepted as Primary Dive Computer?)

Compared to JC, 98% (more like 99.8%) of us on Scubaboard are keyboard warriors. He was a professional commercial diver for decades. He survived where others died. He had the wherewithal to rescue people who were seriously bent and not get bent himself; he tried to rescue these people while on the same dive in the same vicinity. Not as a rescue or recovery diver, as a fellow diver.

If Richie Kohler and/or JC told me to follow some technique or dive plan and any one of you objected, I would listen to Richie or John, and not you. While @Akimbo, @Wookie, @rsingler or @doctormike, et allia, are in same league, even though they may be from different niches, I would still follow Richie and John's advice. I would definitely be saying to myself: Oh f**k, oh s**t, whose advice do I follow?

If Bruce, Lynn, or Pete told me not to follow John or Richie's advice, I would thumb the dive (only because I have a personal relationship with these people).

It is his class. It is his topic. If you don't like the syllabus, find someone who teaches what you want to be taught. Decades of real-life experience matters.

As far as other PDCs v. Shearwater: I am a fan-boy of Shearwater. I don't have any experience with Eon or other comparable computers. I bet if I used one of the other PDCs, I would sing their praises also. It is just a computer; however, the principals of Shearwater have sold themselves to me in person. They are highly ethical people; they hooked me.

cheers,
m

Lots of people idolize their instructors for history and accomplishments. People need to remember that amazing accomplishments does not always equal safe and amazing instruction.

That’s not to be taken as directed at any one instructor. It just seems in some other threads people take their instructors word as fact because they are amazing divers who did crazy dives. I know I did at one point and it was a mistake.
 
Hopefully you gain enough understanding from justifications provided with any advice you get to make your own informed decision for your situation -- regardless of the subject. Decisions are rarely binary. The best option is usually the one with the least onerous compromises.

Want a setting so you NEVER get bent? Set the depth alarm to 15'/5M. It gets a lot murkier after that. :)

Hi Akimbo,

I don't know if you were being somewhat pejorative or just giving advice that you have earned the right to give, but I like your point either way.

At what point beyond 15'/5M does the discussion change from fact based to, for the most part, opinion based?

"The best option is usually the one with the least onerous compromises." Were you thinking Ockham's Razor?

cheers,
markm
 
If Richie Kohler and/or JC told me to follow some technique or dive plan and any one of you objected, I would listen to Richie or John, and not you.

There is no question that if we were on a dive and things went sideways, your odds would be better listening to JC than to me in finding your way out of the wreck or whatever. But, we're not on a dive. We have the luxury to discuss, debate and examine the reasoning. This is particularly true on a subject like this one, where plenty of very, very experienced tech instructors do not impose such a requirement. Asking "why?" and debating it is a healthy thing to do.

What I hope and suspect any of them would say - and what, without qualification, any good instructor would say -- is that they want you to be a THINKING DIVER. Tech training involves learning about decompression theory and dive planning, subjects that are constantly evolving, not just blindly following what your instructor tells you about which algorithm, which GF, etc. Perfectly appropriate to start off students "the instructor's way" but that doesn't mean you don't think about it and make informed decisions as you progress and as the science evolves.

You'll find many experienced divers, vastly experienced divers, and instructors that continue to dive based on what worked for them based on what they started doing 20 years ago, which is out of date and no longer considered best practice. I'm absolutely not suggesting JC is in that category - I don't know him - just generally noting that experience is not the only thing when it comes to dive planning.

If you lack the foundation to assess the arguments yourself, then you're probably right to copy what more experienced diver does, but the point of technical dive training - good training - is to give you the tools to figure some of that out for yourself.
 
At what point beyond 15'/5M does the discussion change from fact based to, for the most part, opinion based?

Like everything related to the human body, our understanding and ability to measure all the variables is too limited to reach absolute conclusions... someday maybe but certainly not in our lifetimes. My comment wasn't meant to be pejorative in any way. My best teachers didn't give me lists of rules. They taught me enough to understand the reasons and limitations for the rules. "X" works for the most people is a factor, but that isn't the same as "X" works 100% of the time for every diver, at least where decompression is concerned.
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom