Peregrine Safety Stop Depth

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That might just mean that all the version between 72 and 78 are Peregrine specific changes. You had a similar thing happen on the Teric new computers come with one firmware, while the release version stayed an older version. They made a new firmware to support a hardware change that only affected new production computers.

But we will see in the coming months if it was a fork or not.

Very possible. Time will tell. At this point the only facts I know for certain are (1) I just got my Peregrine today it came with firmware 78 which is listed as the latest on the SRI website and (2) my Perdix AI latest firmware remains 72.
 
Very possible. Time will tell. At this point the only facts I know for certain are (1) I just got my Peregrine today it came with firmware 78 which is listed as the latest on the SRI website and (2) my Perdix AI latest firmware remains 72.

Firmware difference makes sense currently. All the other Shearwater computers still use the OC Rec mode where as the Peregrine has the Air, Nitrox, 3 Gas in place of them. So they probably branched off the 72 Teric firmware and had some internal versions testing out the new modes getting to finally v78. They have said those modes will be replacing OC Rec on the other models as well, so just handling any device hardware specific changes and also probably letting the dust settles and bug reports come in (not a knock on shearwater but all software has bugs, just a matter of how many and where) and get fixed before moving it to all the other devices. We had similar stuff in my last job where a new product utilized a majority of the older products code base but had some new features that were planning on rolling back to the older devices (when capable).
 
The safety stop description in the Peregrine manual is almost identical to the description in the Perdix Rec Mode manual.
Not surprising - but why does that matter since the Peregrine is the DC being discussed?
 
Not surprising - but why does that matter since the Peregrine is the DC being discussed?
Doesn't matter to me, but it might matter to whomever it was that wanted to be able to "set" the safety stop depth....
 
True, but you do have you get above 20 ft to start the SS countdown - then you can just bounce ÷/- 10 ft for 3-5 minutes :)

That’s good to know, thank you (currently thinking of picking one up).

My Mares Matrix Starts the safety stop the moment I hit 19’. I exhale just a bit too deeply and drift to 20’ and it stops counting. Take another breath and get back up to 19’ and it resumes the countdown. :-I A bit annoying. SB peeps be like “learn how to breathe better, brah.” :D

That’s not the reason I’m looking at this computer. I’ve just been wanting to try the Shearwater Kool-Aid for a bit now.
 
SB peeps be like “learn how to breathe better, brah.”

If anybody tells you that, tell 'em to stick their reg in a different orifice. :p

No, dive computers need some hysteresis in the safety stop depth because conditions are not always perfect; i.e., "you need some slop in the safety stop because you may drop."
 
g2:
No, dive computers need some hysteresis in the safety stop depth because conditions are not always perfect; i.e., "you need some slop in the safety stop because you may drop."
IMHO, the main reason all dive computers allow that "slop" in the safety stop is that it just doesn't matter.

With decompression stops, the computer is trying to calculate if you have off-gassed sufficiently to go safely to the surface. In most (not all) cases, the speed at which you off-gas depends upon your depth. The shallower you are, the faster you off-gas, so decompression divers try to to stay right at their specified decompression depth. If they do that stop 4 feet shallower, they will continue to off-gas, but it won't be quite as fast. The computer knows that, and it adjusts the required time accordingly.

With a safety stop, it is assumed that you are already safe to surface but are just hanging around awhile to be extra safe. If you go too shallow, you are getting too close to the surface and so not being safe; if you get too deep, you are not getting the safety stop benefit an possibly even on-gassing. There is a wide range between those two extremes, and in that range it really doesn't matter all that much.
 
Hi John,

Hey, recently saw you letter in the DAN magazine about older divers. I heartily agree, even if most of my diving is funzie recreational stuff, not tech.

It's been a while since we dove Rock Lake, thanks again for taking me along that time. After completing my PhD in Boulder I moved back to the PNW. I have some of the best diving in Puget Sound right down the street! If you haven't already, you should come out here sometime -- there's a very active tech community that could take you to some amazing, deep dives to WWII wrecks and whatnot. Or you could just go with me to look for critters and old bottles.

IMHO, the main reason all dive computers allow that "slop" in the safety stop is that it just doesn't matter.

Agreed. We understand that a safety stop while doing no-decompression recreational diving is not mandatory but provides an added level of safety. My original question about setting the safety stop trigger depth is all about convenience and preference. At some of the local sites here, the bathymetry 'encourages' a safety stop at around 25fsw since that's where the dropoff is. In the end, though, the exact depth doesn't really matter.

I've since bought a Shearwater Peregrine and I'm very happy with it. It's even smart enough to totally blow off the safety stop if the dive was never very deep in the first place, something my old computer couldn't comprehend. :)

Glenn
 
https://www.shearwater.com/products/peregrine/

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