TexasMike
Contributor
In another thread about Nitrox capable computers (Click here to view) a question came up as to how the new Suunto Vytec would compute a dive profile that WreckWriter recently experienced.
This past weekend, I was able to get my hands on a Vytec and run the profile through the dive simulator and recorded the results.
(NOTE: The information presented here reprepsents a dive that involves mandatory decompression. DO NOT engage in these types of dives unless you have received the appropriate training. Always observe and respect your No Decompression limits (NDL's) and personal limits. Always dive within this limits.)
(NOTE the 2nd: This dive is definitely beyond my personal limites (though I am working on training for it). So if you see me referring to "I descended" and "I ascended" I am referring to using the Vytec's simulation features. I DID NOT PERFORM THIS DIVE IN PERSON. Sorry for that...But I got a few folks who like to dogpile on me when I appear to go beyond my experience and training when I contribute to this board.)
(NOTE the 3rd: The information presented here is an attempt to answer a question and do a little bit of user research in how the Suunto Vytec handles a particular profile. It is not intended to be a critique of functionality. Additionally, this information is not intended to replace proper dive planning for this type of dive. ALWAYS PLAN YOUR DIVE AND DIVE YOUR PLAN!!!)
WW's profile as he posted was a dive on air to 170 fsw for 20 minutes. Settings on the Vytec were Altitude = 0 (sea level) and Personal adjustment = 0 (fit diver and perfect diving conditions) and Model = Air (The Vytec can be set to model Air, Nitrox, or Guage).
I ran the simulator twice and here was the results:
(humorous side note: I forgot to turn off the air integrated feature on my first try. So when the simulation started, the computer "assumed" I had started the dive with 2900psi. Well, since we all know that at 170 fsw, your going through breathing gas very quickly. I "ran out of air" during the simulation 17 minutes in. Proved again that proper dive dive planning is a must! Especially on how much gas you need to take with you. So I turned off the air integration feature and started over)
1st try: This was my first time to use the dive simulator feature on a Suunto computer, so on this try, I pressed the button that caused the computer to "descend" one foot at a time at a moderate pace until the target depth of 170 was reached. (depth reached at 5 minutes into dive)
7 minutes into the dive while at 170 fsw the computer did provide the warning that the NDL's had been exceeded and began to add then lower the mandatory stop ceiling (10 feet) and tack on time (8 minute stop). The ceiling depth replaces the max depth display, and the ASC TIME replaces the NDL time.
As time at 170 fsw progressed, the ceiling kept dropping and more time was added to the ASC TIME display.
After 20 "simulated" minutes had elapsed (during simulation, 15 seconds real time = 1 minute simulated), I noted the first "stop" and the total ascent time. Which was 40 fsw and ASC TIME=39 min.
Then I started repeatedly pressing the button that caused the computer to ascened. Occasionally I got the ascent rate warning and would slow down my button pushing. When I reached 40 fsw, the ASC TIME had increased to 43 minutes (which I view as "correct" since I was still on-gassing at depth as I was rising to the first top).
The entire simulated run resulted in the following stops and remaining ascent times. I should point out that I would only ascend to the next stop (eg from 40 to 30 feet) when the computer said it was okay to be at that new shallower depth.
Second Dive: Same parameters at first dive, but this time I held down the buttons on both the descent and ascent to move as fast as the Vytec would go on the simulation.
170 fsw was reached in less than 3 minutes. NDL ran out at 5 minutes (again, 10 fsw ceiling, 8 minutes).
At 20 minutes elapsed time, I began the ascent by holding down the button...as expected, I got beeped at with an ascent rate warning. But there was an interesting result in the deco profile because of this as shown below. As before, I did not ascend until I was cleared for that depth.
Now here is where we figured out how comparitively conservative the Vytec appears to be.
From the U.S. Navy Standard Air Decompression Table (2000) as published in the TDI A Diver's Guide To Decompression Procedures -- Theory, Equipment, and Procedures, (copyright J. Odom and International Training 2000, Rev 1b), this same dive results in the following decompression obligation:
Since I don't have any other other well known and respected decompression modelling sofware (such as V-planner), I wasn't able to do a comparison with those. But I would be interested in what someone who does have it comes up with.
Anyhow, this experiment was interesting and I enjoyed conducting it. Your questions and comments are welcome.
This past weekend, I was able to get my hands on a Vytec and run the profile through the dive simulator and recorded the results.
(NOTE: The information presented here reprepsents a dive that involves mandatory decompression. DO NOT engage in these types of dives unless you have received the appropriate training. Always observe and respect your No Decompression limits (NDL's) and personal limits. Always dive within this limits.)
(NOTE the 2nd: This dive is definitely beyond my personal limites (though I am working on training for it). So if you see me referring to "I descended" and "I ascended" I am referring to using the Vytec's simulation features. I DID NOT PERFORM THIS DIVE IN PERSON. Sorry for that...But I got a few folks who like to dogpile on me when I appear to go beyond my experience and training when I contribute to this board.)
(NOTE the 3rd: The information presented here is an attempt to answer a question and do a little bit of user research in how the Suunto Vytec handles a particular profile. It is not intended to be a critique of functionality. Additionally, this information is not intended to replace proper dive planning for this type of dive. ALWAYS PLAN YOUR DIVE AND DIVE YOUR PLAN!!!)
WW's profile as he posted was a dive on air to 170 fsw for 20 minutes. Settings on the Vytec were Altitude = 0 (sea level) and Personal adjustment = 0 (fit diver and perfect diving conditions) and Model = Air (The Vytec can be set to model Air, Nitrox, or Guage).
I ran the simulator twice and here was the results:
(humorous side note: I forgot to turn off the air integrated feature on my first try. So when the simulation started, the computer "assumed" I had started the dive with 2900psi. Well, since we all know that at 170 fsw, your going through breathing gas very quickly. I "ran out of air" during the simulation 17 minutes in. Proved again that proper dive dive planning is a must! Especially on how much gas you need to take with you. So I turned off the air integration feature and started over)
1st try: This was my first time to use the dive simulator feature on a Suunto computer, so on this try, I pressed the button that caused the computer to "descend" one foot at a time at a moderate pace until the target depth of 170 was reached. (depth reached at 5 minutes into dive)
7 minutes into the dive while at 170 fsw the computer did provide the warning that the NDL's had been exceeded and began to add then lower the mandatory stop ceiling (10 feet) and tack on time (8 minute stop). The ceiling depth replaces the max depth display, and the ASC TIME replaces the NDL time.
As time at 170 fsw progressed, the ceiling kept dropping and more time was added to the ASC TIME display.
After 20 "simulated" minutes had elapsed (during simulation, 15 seconds real time = 1 minute simulated), I noted the first "stop" and the total ascent time. Which was 40 fsw and ASC TIME=39 min.
Then I started repeatedly pressing the button that caused the computer to ascened. Occasionally I got the ascent rate warning and would slow down my button pushing. When I reached 40 fsw, the ASC TIME had increased to 43 minutes (which I view as "correct" since I was still on-gassing at depth as I was rising to the first top).
The entire simulated run resulted in the following stops and remaining ascent times. I should point out that I would only ascend to the next stop (eg from 40 to 30 feet) when the computer said it was okay to be at that new shallower depth.
Ceiling depth -- ASC TIME remaining
===========================
40 fsw................39 min (recorded while at 170 fsw & starting ascent)
40 fsw................43 min (having reached 40 fsw)
30 fsw................40 min
20 fsw................37 min
15 fsw................31 min
10 fsw................27 min
Second Dive: Same parameters at first dive, but this time I held down the buttons on both the descent and ascent to move as fast as the Vytec would go on the simulation.
170 fsw was reached in less than 3 minutes. NDL ran out at 5 minutes (again, 10 fsw ceiling, 8 minutes).
At 20 minutes elapsed time, I began the ascent by holding down the button...as expected, I got beeped at with an ascent rate warning. But there was an interesting result in the deco profile because of this as shown below. As before, I did not ascend until I was cleared for that depth.
Ceiling depth -- ASC TIME remaining
===========================
43 fsw................48 min (recorded while at 170 fsw & starting ascent)
45 fsw................48 min (the ceiling dropped during my fast ascent)
48 fsw................48 min (it dropped again while at 45 fsw...probably due to fast ascent)
40 fsw................47 min
30 fsw................43 min
20 fsw................40 min
10 fsw................31 min
Now here is where we figured out how comparitively conservative the Vytec appears to be.
From the U.S. Navy Standard Air Decompression Table (2000) as published in the TDI A Diver's Guide To Decompression Procedures -- Theory, Equipment, and Procedures, (copyright J. Odom and International Training 2000, Rev 1b), this same dive results in the following decompression obligation:
- Time to first stop: 5 minutes (assumes 30 ft/min ascent rate)
20 foot stop for 4 minutes
10 foot stop for 15 minutes
Total ascent time: 24:40 minutes
Since I don't have any other other well known and respected decompression modelling sofware (such as V-planner), I wasn't able to do a comparison with those. But I would be interested in what someone who does have it comes up with.
Anyhow, this experiment was interesting and I enjoyed conducting it. Your questions and comments are welcome.
