Oceanic DSAT or PZ+ on backup computer

[JohnN]

My primary computer is a Perdix AI (love it!!) My backup was an old Suunto that has suffered the pressure sensor failure and has started diving on its own.

The Oceanic Geo 2.0 would seem a reasonable backup replacement. Which of the two algorithms (DSAT or PZ+) would best match the default Perdix algorithm?

 

[scubadada]

DSAT is not too far from 45/95, PZ+ is closer to 40/85. Only the GF high relates to no stop diving. There are some differences when considering 1st dive vs. repetitive dives.

 

[JohnN]

DSAT is not too far from 45/95, PZ+ is closer to 40/85. Only the GF high relates to no stop diving. There are some differences when considering 1st dive vs. repetitive dives.

Thank you!

 

[scrane]

DSAT is about as high as I want to go, so I'd set up the GEO 2 in DSAT to avoid locking it out and having a hard red line. If the Perdix fails ( ! ) I would continue with the GEO in PZ+ for subsequent dives.

 

[JohnN]

DSAT is about as high as I want to go, so I'd set up the GEO 2 in DSAT to avoid locking it out and having a hard red line. If the Perdix fails ( ! ) I would continue with the GEO in PZ+ for subsequent dives.

Thanks. My last "failure" was purely mental (I left the Perdix on-shore)

 

[Saboteur]

My primary computer is a Perdix AI (love it!!) My backup was an old Suunto that has suffered the pressure sensor failure and has started diving on its own.

The Oceanic Geo 2.0 would seem a reasonable backup replacement. Which of the two algorithms (DSAT or PZ+) would best match the default Perdix algorithm?

I currently dive two Suunto’s and am thinking about a Perdix or Ratio computer. How did you have the Perdix and Suunto set up to be “close”? How did they compare on single and repetitive dives?

 

[scubadada]

Hi @Saboteur

Your question might be affected by which Suunto computers you dive and what your settings are. Most Suunto computers run Suunto RGBM, generally considered moderate to conservative. The D9tx runs Technical RGBM, the DX. Eon Steel and Core run Fused RGBM, the D5 runs Fused RGBM 2. These algorithms can be more liberal.

For Suunto RGBM, I would guess that 40/85 would be a good place to start on a Perdix. I would guess that 35/75 would be too conservative. Once you have some experience, you could adjust using custom GF to get where you want to be.

I don't have personal experience with Ratio. Ratio runs Buhlmann ZH-L16B rather than 16C and might be a little more liberal in some circumstances. The presets on Ratio computers are quite different than with Shearwater, 93/93, 90/90, 80/80, 75/75, 30/90, 20/89. The Easy and Deep models only have presets and no custom GF. You must go with the Tech+ model to get custom GF. I would guess that 80/80 might be the best match, if too conservative, you could try 90/90.

Best of luck, maybe you can tell us what you do and how it worked out

 

[jaseUK666]

DSAT is not too far from 45/95, PZ+ is closer to 40/85. Only the GF high relates to no stop diving. There are some differences when considering 1st dive vs. repetitive dives.

Maybe if you're just comparing no deco times but neither of those algorithms are anything like 40/85 for example. They don't do the deep.stops that the 40 would give for for a start.

I've got an older Oceanic and with the PZ+ algorithm selected, compared to my main computer on 30/90, it gives about the same no deco times. On deco dives, it wants the majority of stops at 3m but doesn't penalize you for doing them deeper when following the main computer. Generally it gives 2 mins more deco on short stops but once you're over 10 mins accelerated, it gives way more. I recall it giving me 17 mins vs 10 on my OSTC.

 

[scubadada]

Yes, was comparing no deco times for rec diving. These algorithms might not match for deco, especially with a low GF low.

 

[outofofficebrb]

I have had about 250 dives with DSAT backing up my Perdix on either rec med or low setting without issues. My understanding is that Oceanic seems DSAT more liberal than the Z+ and you want the more liberal option than your primary computer or in general for an ideal backup.