Decisions on a Dive Computer

[scubadada]

The Aqua Lung i330R is an interesting computer from them. It is their 1st computer that does not run PZ+, but runs Buhlmann ZH-L16C "Sport version". It has 3 presets that are said to be 90/90, 35/85, and 35/70. The 90/90 is probably a bit more liberal than PZ+, that runs around a GF high of 85.

I emailed them to ask whether there were any plans to add custom GF to the i330R or offer that on future computers. They answered me, but informed me about the case O-ring recall (link above) and did not answer my question. A GF high of 90 does not suit me, but now that PZ+ is not their only algorithm, there is a chance that a more flexible computer may be offered in the future. The price of $359 is competitive.

 

[poseident]

Yes the G2 is supported by standard decompression algorithms.Thankyou for your reply.
Just wondering if you would have any recommendations of what path of training I could pursue in order to allow myself to dive some of the WW II wrecks at Chuck Lagoon Micronesia which would be around the 55-60 meter depth?
I have logged approximately 200 or so NDL dives.

Shane,
I just wanted to point out that there are fantastic wrecks in Chuuk that are less than 55-60 meters. I understand the pull of the San Francisco Maru, but would rather hang on two or three times as long on the Shinkoku myself. Chuuk is about the last place on earth you want to have an accident. Lastly, if you do make it, consider at least one day (maybe a mid-trip day) diving the outer reef. It's nice to take a break from depth and the reefs there are (or at least WERE) very underrated. Most people won't consider "wasting a day" on the reefs, but I enjoyed it.

 

[wetb4igetinthewater]

About the G2, does anyone have any information on the research for this (from https://ww2.scubapro.com/en-GB/HKG/instruments/computers/products/g2.aspx):

ONLY SCUBAPRO computers utilize heart rate, skin temperature, breathing rate and water temp when calculating diving profiles.

And any ideas on how these items affect the calculations?

I tend to shy away from proprietary/closed algorithms.

 

[BoltSnap]

ONLY SCUBAPRO computers utilize heart rate, skin temperature, breathing rate and water temp when calculating diving profiles.

And any ideas on how these items affect the calculations?

It makes the NDL's more conservative. You can turn off these factors so the computer doesn't take them into consideration in calculating NDL's. It is an "option" not a set "always on" feature.

You can communicate directly with Scubapro's technical services on the website and they respond promptly. I have communicated with them many times and they are always approachable, responsive and they listen and open for suggestions.

I tend to shy away from proprietary/closed algorithms.

EACH and every manufacturer of recreational dive computer add their own fudge factor into the original algorithm according to their own formula and they don't tell you about the details, it is their design. They are based on the open algorithm but they tweak to their liking, practically everybody does that.


Did you read this document in the link you provided???

https://ww2.scubapro.com/en-GB/HKG/heart-rate-monitoring-diving.aspx

 

[scubadada]

Buhlmann alterations with GF high and GF low are relatively transparent, a % of the M-value.

 

[scubadada]

It makes the NDL's more conservative. You can turn off these factors so the computer doesn't take them into consideration in calculating NDL's. It is an "option" not a set "always on" feature.

You can communicate directly with Scubapro's technical services on the website and they respond promptly. I have communicated with them many times and they are always approachable, responsive and they listen and open for suggestions.



EACH and every manufacturer of recreational dive computer add their own fudge factor into the original algorithm according to their own formula and they don't tell you about the details, it is their design. They are based on the open algorithm but they tweak to their liking, practically everybody does that.


Did you read this document in the link you provided???

https://ww2.scubapro.com/en-GB/HKG/heart-rate-monitoring-diving.aspx

I believe that the baseline algorithm for Buhlmann ZH-L16 ADT MB is more conservative than native Buhlmann. All the "human factors" increase the conservatism. Interpret this as you please.

 

[BoltSnap]

I believe that the baseline algorithm for Buhlmann ZH-L16 ADT MB is more conservative than native Buhlmann. All the "human factors" increase the conservatism. Interpret this as you please.

You turn on and turn off the features as you please.

 

[wetb4igetinthewater]

It makes the NDL's more conservative. You can turn off these factors so the computer doesn't take them into consideration in calculating NDL's. It is an "option" not a set "always on" feature.

Yes, but they tout it like a major feature that is beneficial. Where's the science backing this?

You can communicate directly with Scubapro's technical services on the website and they respond promptly. I have communicated with them many times and they are always approachable, responsive and they listen and open for suggestions.



EACH and every manufacturer of recreational dive computer add their own fudge factor into the original algorithm according to their own formula and they don't tell you about the details, it is their design. They are based on the open algorithm but they tweak to their liking, practically everybody does that.

You have to admit, this is more than just a fudge factor.

Did you read this document in the link you provided???

https://ww2.scubapro.com/en-GB/HKG/heart-rate-monitoring-diving.aspx

I actually did.

I was hoping to find references to the peer reviewed research stating how heart rate, skin temperature, and respiration rate impact nitrogen absorption. I didn't find anything of value there for the information I was seeking.

 

[LandonL]

Yes, but they tout it like a major feature that is beneficial. Where's the science backing this?

There are general trends, but nothing quantifiable. Honestly it is more a bit of snake oil marketing than firm science.

I was hoping to find references to the peer reviewed research stating how heart rate, skin temperature, and respiration rate impact nitrogen absorption. I didn't find anything of value there for the information I was seeking.

There isn’t any.

 

[Blackcrusader]

Buhlmann alterations with GF high and GF low are relatively transparent, a % of the M-value.

What I notice is that if a have a dive buddy for several days using a Suunto they have far less time to NDL on repeat dives than I do.
By the third day they often would need to either go into deco or stay 5m-10m or more shallower. That is based on doing say 9 or 10 dives in 3 days. Suunto are very conservative if you are doing lot's of dives over period of days.