Another perspective, a great way to get a $300 + discount on a Teric or perdix is to not buy something else first.
What to Choose?
- Thread starter Ridnick
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Complete nonsense. I run an Eon Steel, as does my wife, as do quite a few people here. No problems whatsoever It's a very reliable computer. I also run a Perdix, which is Ok but IMO its only advantage over the Eon is that it can display 2 gasses simultaneously - useful for SM if you're too lazy to read the SPG's in front of your face..
I've also just completed a trip with 48 repetitive dives over 12 days - all 60min in nitrox max depths of 30m. There was No discernable difference between the NDL's given by Buhlmann and Fused RGBM.
There is a huge prejudice against Suunto here on SB, and while the company is far from perfect most of the negative comments are regurgitated nonsense.
Depending on the region of the purchaser then the pricing of different products may or may not be a greater influence rather than capability
Many of the negative comments have to do with their use of a proprietary version of RGBM. It will be interesting to see if that those opinions begin to change once they incorporate Buhlmann GF as has been rumored.
As a vacation diver, the deeper I dig into ZHL the less happy I am with its treatment of repetitive multi-day schedules. I am not convinced RGBM (whatever it is) is doing it right, but at least they were designed in some form. I am not sure which of the proprietary RGBM, proprietary DSAT, and open ZHL is the lesser evil for my use -- it's academic of course, they're all conservative enough to not bend people under normal circumstances.
I get paid for writing open source code, I can promise you that until you see the actual code with comments and explanations, the difference between "proprietary" RGBM and "non-proprietary" implementation of ZHL with GFs is six vs half a dozen.
- Messages
- 19,792
- Reaction score
- 18,657
- Location
- Philadelphia and Boynton Beach
- # of dives
- 1000 - 2499
It more or less ignores multi day diving.
It assumes on and off gassing is symmetrical and doesn’t do anything to explicitly take into account repetitiveness dives. It relies on the left over gas from the earlier dive.
It doesn’t scale for depth.
It does nothing for sawtooth profiles.
You know perfectly well what's bothering me about gradient factors on no-stop dives, we just had a whole thread about it. As for repetitive multi-day schedules, Haldane model is strictly symmetrical, the only way you get any gas accumulation in slower tissues is saturation diving. If you look at the models designed for multi-day schedules
- RGBM has its slowest compartment at 10 hours, at least in my computer, plus some sort of conservatism factor "on the side" that tracks prior history on the "timescale of days" (quoting Wienke).
- DSAT has slower compartments but only really tracks the 6-hour one. Their conservatism factor on the side is "take every 6th day off" (quoting the original DSAT report).
By numbers, the slower compartments in ZHL don't matter for my kind of diving, and there is no tracking of multi-day accumulation. Maybe it's right and there is no accumulation, I don't know. I know that a few people from Thalmann to Powell to Wienke seem to disagree with that symmetrical thing.
Edit: Buhlmann himself noted that off-gassing seems to get slower when you sleep (in Decompression - Decompression Sickness), i.e. it's not strictly symmetrical once scaled to multi-days, but his model does not do anything about that.
- RGBM has its slowest compartment at 10 hours, at least in my computer, plus some sort of conservatism factor "on the side" that tracks prior history on the "timescale of days" (quoting Wienke).
- DSAT has slower compartments but only really tracks the 6-hour one. Their conservatism factor on the side is "take every 6th day off" (quoting the original DSAT report).
By numbers, the slower compartments in ZHL don't matter for my kind of diving, and there is no tracking of multi-day accumulation. Maybe it's right and there is no accumulation, I don't know. I know that a few people from Thalmann to Powell to Wienke seem to disagree with that symmetrical thing.
Edit: Buhlmann himself noted that off-gassing seems to get slower when you sleep (in Decompression - Decompression Sickness), i.e. it's not strictly symmetrical once scaled to multi-days, but his model does not do anything about that.
I'm not sure what you mean by "no tracking of multi-day accumulation". My Shearwaters certainly show the slower compartments loading up over the course of a multi-day trip, but on liveaboard schedules using 32% they don't accumulate much.
DSAT report is showing slower compartments loading on air, but it takes full 6 days to get the loading to where it begins to matter. So what they did is say "take the 6th day off".
I think that's a noticeably cheaper option than a $1K+ computer that draws you a pretty heat map and you have to have enough clue to understand what it actually tells you. But like I said, they're all conservative enough to not get people bent so... whatever.
I think that's a noticeably cheaper option than a $1K+ computer that draws you a pretty heat map and you have to have enough clue to understand what it actually tells you. But like I said, they're all conservative enough to not get people bent so... whatever.
All the fast and medium compartments which will limit your dives are back to empty overnight. The longer compartments which you see mounting up are not going to get high enough to matter. So there is no effective mechanism to carry load overnight. You can test this by planning a series of dives in MultiDeco. Or you could code up GF and have a play. I suspect that is what dmaziuk has done. It is not too hard. I notice that people that have done that are generally more sceptical of it than average.
Other schemes explicitly change the limits, on compartments which actually influence the dive, according to the generally accepted principles of deco, so multi day, multi dives in a day, short SI, sawtooth.
Alternatively, you can manually apply those rules by reducing the GF high when doing that kind of diving.
Similar threads
