Perdix & Deco time

[Jackie Treehorn]

Fair point. But I could utilize a perdix without being as knowledgeable about it's settings as others.

Not a fair point at all. Ignore that dude.

Keep diving, keep learning. You will grow into all of its capabilities if you want. And if you don't thats ok too. That computer is perfect for all experience levels.

 

[WinfieldNC]

If you don't feel comfortable enough to change your GF settings and haven't learned to use your computer I would be very careful about doing decompression dives. You obviously aren't trained for deco dives. I realize that your point is that with different settings you wouldn't be in deco but this is still concerning.

 

[hedonist222]

It does what it's supposed you and shearwater has excellent after-sales support.

I mentioned this in another thread but I thin it's worth mentioning again because we should expect this sort of service.

A day before traveling to Indonesia via Singapore. I put in a new battery, but it didn't start up.
Got the computer in June and did about 60 dives on it and changed the battery thrice. Changed it like I usually do. It's fully dry, gently unscrew, put in new battery and gently screw the cap back after making sure the two o rings are in good condition.
Had to take out and put in the battery about 2 dozen times before it started up. Obviously tried several new batteries.

I was obviously a bit worried because I was about to do about 30 dives over 10 days.
I emailed them and let them know I was going to be in Singapore for two days before immersing deep into the jungles of Indonesia.
Shearwater worked profusely to ensure they put s a new computer on my wrist during these two days in Singapore - through their Singapore retailers.
Originally they said they'd swap my malfunctioning one for a loaner. But that turned into swapping my malfunctioning one for a brand new one.

Excellent after sales support.

 

[hedonist222]

If you don't feel comfortable enough to change your GF settings and haven't learned to use your computer I would be very careful about doing decompression dives. You obviously aren't trained for deco dives. I realize that your point is that with different settings you wouldn't be in deco but this is still concerning.

I agree that decompression dives should be done by the qualified/experienced but if I set it to OC Rec, it defaults to medium conservatism (40/85).
When I set it to OC Tec, it defaults to high conservatism (30/70) because Shearwater feels that if you're in Tec mode, defaulting should be at highest conservatism.
But, I prefer the Tec interface over Rec, so why shouldn't I change GF to Rec GF settings?

Or do you mean, I shouldn't adjust GF beyond the preset settings?

 

[WinfieldNC]

I agree that decompression dives should be done by the qualified/experienced but if I set it to OC Rec, it defaults to medium conservatism (40/85).
When I set it to OC Tec, it defaults to high conservatism (30/70) because Shearwater feels that if you're in Tec mode, defaulting should be at highest conservatism.
But, I prefer the Tec interface over Rec, so why shouldn't I change GF to Rec GF settings?

Or do you mean, I shouldn't adjust GF beyond the preset settings?

I think it’s fine to use your computer in Tec mode and to I think it’s fine to adjust your GF to 45/95 while in Tec mode to match the least conservative setting found in Rec mode. I would not exceed your NDL in any setting without a strong understanding of decompression diving (gas planning, virtual ceiling, equipment redundancy, etc...).

 

[hedonist222]

I think it’s fine to use your computer in Tec mode and to I think it’s fine to adjust your GF to 45/95 while in Tec mode to match the least conservative setting found in Rec mode. I would not exceed your NDL in any setting without a strong understanding of decompression diving (gas planning, virtual ceiling, equipment redundancy, etc...).

Fully agree with the bolded text.

 

[Glenn Williams]

Guys, I have a new Perdix ai and have been using an Eon Core. We are going on a scuba trip to the Cayman Islands in January.

This trip will be my first dive with my brand new Perdix ai. I will be diving air in open circuit mode. I am Nitrox certified but do not anticipate diving Nitrox.

Question for those in the know. Should I leave the GF in default mode or leave as is?

I have been diving my core at the most aggressive setting.

Thanks in advance

Glenn

 

[KenGordon]

I think it’s fine to use your computer in Tec mode and to I think it’s fine to adjust your GF to 45/95 while in Tec mode to match the least conservative setting found in Rec mode. I would not exceed your NDL in any setting without a strong understanding of decompression diving (gas planning, virtual ceiling, equipment redundancy, etc...).

Are you sure about recommending 45/95 for a person who professes not to know much about deco and the risks? Maybe he is diving in the cold, old, fat, drinking in the evening, doing repetitive dives, bouncing up and down, etc..

Personally I am much less scared by people executing simple backgas deco dives than those doing four to the NDL dives each day for a week.

 

[hedonist222]

Are you sure about recommending 45/95 for a person who professes not to know much about deco and the risks? Maybe he is diving in the cold, old, fat, drinking in the evening, doing repetitive dives, bouncing up and down, etc..

Personally I am much less scared by people executing simple backgas deco dives than those doing four to the NDL dives each day for a week.

I get your point and it's valid.
But he wasn't recommending this GF profile - shearwater is , when they set it as default in Open Circuit Recreational diving mode.

He's only saying that I can match this default setting when I use Open Water Technical dive mode.

 

[KenGordon]

Guys, I have a new Perdix ai and have been using an Eon Core. We are going on a scuba trip to the Cayman Islands in January.

This trip will be my first dive with my brand new Perdix ai. I will be diving air in open circuit mode. I am Nitrox certified but do not anticipate diving Nitrox.

Question for those in the know. Should I leave the GF in default mode or leave as is?

I have been diving my core at the most aggressive setting.

Thanks in advance

Glenn

Why not dive nitrox?

These people cannot answer you really regarding the eon vs the Perdix.

The Perdix uses a model which is simplistic and does nothing about the impact of repeat dives other than the basic half time decay of dissolved gas.

On the other hand the Eon reduces your limits, more that half time decay would allow for, for a couple of hours. If you were thinking in GF numbers then it would be like first dive at GF90, automatically changing to GF70 at the end of the first dive, then to GF80 after an hour and back to GF90 after two hours (note these numbers are made up for illustration).

What this means is that just because p-2 didn’t bend you on the Eon doesn’t mean that an apparently equivalent setting on the Perdix is good for you, because it isn’t really equivalent.

If diving both computers you should decide which one to follow (ie look at on the dive for NDL/deco numbers) and set it to something sensible (x/85 or p0). Set the other to something you will not accidentally bend if not paying it attention, eg 50/99 or p-2. Really though, even a minor bit of attention is enough not to bend a second computer.

Personally I would not dive a x/95 GF profile. In Cayman though you are likely to be ascending on the shallow reef so be surfacing quite well off-gassed. If the purpose in setting the computer like that is to pretend you were never in deco for some DM then fine, if the purpose is to control surfacing then maybe not...