Hydro Space Explorer computer deco model

[StraitsdiverGeo]

I was reading the last thread on RGBM vs. Buhlmann algorithms, I did not wish to hijack some ones thread. So here I am.

The first question is and (Dr. Deco please feel free to jump in) does any one have a opinion good or bad of the decompression models used by the HS Explorer?
It’s my understanding the Explorer in some of it’s deco schedules uses both the RGBM, and Buhlmann together. Eg; (CF 9)

Question 2; I made use of this schedule last summer for dives down to 200 fw. Making use of the CF 9 schedule and Nitrox 50 @ 70', and then 100% 02 @ 20'. I did so with the understanding that this was the best practice to avoid getting a hit. Also, I understand that no schedule is full proof, but it seem to be the best out there.
I’m sure that this opening a huge can of worms, but please, can anyone put a little light on this for me?

Regards, George

 

[wedivebc]

I was reading the last thread on RGBM vs. Buhlmann algorithms, I did not wish to hijack some ones thread. So here I am.

The first question is and (Dr. Deco please feel free to jump in) does any one have a opinion good or bad of the decompression models used by the HS Explorer?
It’s my understanding the Explorer in some of it’s deco schedules uses both the RGBM, and Buhlmann together. Eg; (CF 9)

Question 2; I made use of this schedule last summer for dives down to 200 fw. Making use of the CF 9 schedule and Nitrox 50 @ 70', and then 100% 02 @ 20'. I did so with the understanding that this was the best practice to avoid getting a hit. Also, I understand that no schedule is full proof, but it seem to be the best out there.
I’m sure that this opening a huge can of worms, but please, can anyone put a little light on this for me?

Regards, George

According to the manual on pg 53 comarison chart CF9 = ZH-L16 Buhlmann only CF 0-2 use RGBM

I use CF 2 for most of my deep dives as I prefer the deeper stops provided by the RGBM. CF9 will get you shallower sooner but you'll stay in the water longer.

 

[StraitsdiverGeo]

Hi wedivebc,

Please look at page 34 and read the first pargraph and let me know what you think. Maybe I'm missing something, but half way down it says, "CF9 is the most conservative of the Buhlmann algorithms. A dervation of the Reduced Bubble Gas Model (RGBM)is applided to provide deeper inital stops in Buhlmann CF's withn 'F' number less than100." I'm going to do some more reading tonight and report back. I looked at page 53 and will look again, but I see what you talking about on page 50 in the sample Cf comparison table.
So bottom line, do you think that CF2 is safer than say CF9??? I'm interested in what you have to say on the subject. Most dives I will add my own 1 minute stops at 1/2 of my max depth and most of the time my computer will drop off deeper required stops as I ascend.

Regards, George

 

[wedivebc]

Hi wedivebc,

Please look at page 34 and read the first pargraph and let me know what you think. Maybe I'm missing something, but half way down it says, "CF9 is the most conservative of the Buhlmann algorithms. A dervation of the Reduced Bubble Gas Model (RGBM)is applided to provide deeper inital stops in Buhlmann CF's withn 'F' number less than100." I'm going to do some more reading tonight and report back. I looked at page 53 and will look again, but I see what you talking about on page 50 in the sample Cf comparison table.
So bottom line, do you think that CF2 is safer than say CF9??? I'm interested in what you have to say on the subject. Most dives I will add my own 1 minute stops at 1/2 of my max depth and most of the time my computer will drop off deeper required stops as I ascend.

Regards, George

I wish I understood RGBM better to give you an educated answer but it is my understanding that cf9 is a Buhlmann approximation of a RGBM acsent curve but will only have a limited range. If you compare a true RGBM model to a GF altered Buhlmann you will see at some point (depth/time) the variance becomes greater.
The truth is there is no perfect decompression model and when you do enough dives of the same type using the same model you will start to "feel" when they are working and when they need adjusting.

 

[StraitsdiverGeo]

Dave,

Many Thanks!! I too wish I knew more about some of the algorithms. And I too understand what you are saying about the "Feeling" of when a dive model is workimg or not. I started out using CF 2 (RBGM) and had one instance where i was woundering if I was bent. I had a little pain in behind my sholder blade. It could have been just a sprain. I havd to climb back aboard during rough seas?? That's when I changed to useing CF 9, todate, no issues. I'm going to ask Hydro Space People a few questions and if I come acrossed anything new I'll share it with you.

Regards, George

 

[Dr Deco]

I am sorry that I could not reply to this question. I have no knowledge of the algorithm in these computers.