Shearwater Peregrine

[Belzelbub]

Is there a way to delete the words and numbers for "safety stop" from the screen entirely, so that they only appear when you actually reach your stop depth, and NDL can thus be displayed with a larger font size?

No. Not while keeping Safety Stop active, at least. If using the adaptive safety stop, it won’t actually display “Safety Stop” unless the dive meets the threshold, but I don’t believe that increases the font size any.

 

[rsingler]

Another question... What is the recommendation of the default gradient factors (GF) settings for recreational diving and doing a dive with no mandatory decompression stops and a maximum of 40 meters deep? The default conservatism of the system is medium (40/85), Is this good for diving with other divers with other computers with different algorithms? Thanks

I know you've received a good answer above, but here are my thoughts.
See section 9.2 of the manual, and take my advice with a grain of salt...
1) The default GF's carry a bit of legacy bias due to older beliefs about optimal protection against DCS.
2) For no-stop dives, the lower the "high" number (e.g., the 85 in your 40/85 example), the shorter your NDL by a little bit, and the safer the dive from a DCS standpoint, though it's complex.
3) Therefore, choosing Conservative (35/75) should be safer. In fact, I actually dive my Shearwater to XX/70 for no-stop diving.
4) BUT... the legacy bias pairs a lower GFHi with a lower GFLo. That shouldn't mean anything for a no-stop dive, because the GFLo never comes into play, for all intents and purposes. But should you have an unintended deco requirement (you exceeded NDL), then your GFLo will give you a deeper first stop than I believe is best.

Without derailing this thread (because Gradient Factors is discussed ad nauseum elsewhere) I would recommend you choose either Conservative (GF 35/75) or a custom GF like the one I dive, which is GF 50/70. I am happy to sacrifice 5 minutes of bottom time for what I believe to be added safety when doing 25 dives in a week on vacation.

So nobody in their right mind is going to tell you what numbers to use.

Except me.

 

[Couv]

Except me.

Operative term: Right mind.

 

[rsingler]

Is this good for diving with other divers with other computers with different algorithms?

As for matching with what other divers in your group are doing, meh. If you're consistently the first one up, work that out with your buddy. Your assessment of your safety should be the deciding factor. More likely, with SurGF to rely on with your Shearwater (read about that elsewhere), I'd be very surprised if 50/70 crimped your style on repetitive dives more than many other (cough, cough, Suunto) computers out there.

For no stop dives, I don't really care what algorithms my group is diving. At all! I dive with my friends, and we go up when folks have to ascend. But me? I don't leave 15 feet for the surface until my SurGF is less than 70. And that's as far off topic as I'm going to go in the Peregrine thread. If that's worth a separate discussion, I'll leave it to one of you to start yet another thread on Gradient Factors.

 

[dmaziuk]

Operative term: Right mind.

There's 10 kinds of people: those who get binary system, and those who don't.

2) For no-stop dives, the lower the "high" number (e.g., the 85 in your 40/85 example), the shorter your NDL by a little bit, and the safer the dive from a DCS standpoint, though it's complex.
3) Therefore, choosing Conservative (35/75) should be safer. In fact, I actually dive my Shearwater to XX/70 for no-stop diving.

M-value is chosen to generate -- statistically -- less than X in Y incidents of clinical DCS on dives that don't exceed it. The "X in Y" of a given model is chosen based on a variety of factors including the target demographic, type of dives, and the predicted DCS incidence that somebody on the design team deemed "acceptable".

But since the process is not linear, it does not follow that setting the M-value to 75% of its original "X in Y" will make you 25% "safer". If the given model has not been tested and calibrated for all possible M-value settings from 100/100 down, we really don't know if 35/75 is any safer than 40/85 for any rational definition of "safer".

I get this feeling that all these SurfGF displays and "recreational GF" presets etc. do, is create the expectation of safety in the mind of the users, that the actual reality does not deliver and never intended to.

 

[Anthony A.]

Anyone know of a nato strap that will work with this?