THE FOLLOWING POST DISCUSSES INFORMATION ABOUT PLANNED DECOMPRESSION DIVING AND THE USE OF DIFFERENT GAS MIXTURES IN SUCH DIVING.
:nono:DO NOT ENGAGE IN THIS FORM OF DIVING OR USE OF DIFFERENT GASSES DURING A DIVE UNTIL YOU HAVE RECIEVED THE PROPER TRAINING FROM AN ACCEDITED AGENCY AND EXPERIENCED INSTRUCTOR. IT'S DANGEROUS STUFF TO DO ON YOUR OWN WITHOUT TRAINING AND CAN RESULT IN SERIOUS INJURY INCLUDING DEATH
ALSO NOTE THAT I HAVE ONLY RECENTLY COMPLETED MY TRAINING IN THIS TYPE OF DIVING. SO THERE MIGHT BE AN UNINTENTIONAL MISTAKE IN MY THINKING AND WHAT I'VE WRITTEN.
AGAIN, SEEK PROPER INSTRUCTION BEFORE EMBARKING ON THIS AVENUE OF DIVING.
First, let's talk in generalities...
According to my TDI instructors, if you are performing ANY planned decompression diving and blow through the ascent profile that the computer has determined, it will lock you out.
And based upon what my little bit of research has determined, this applies to all computers. (except perhaps the VR3, of which I have no experience with other than vicariously through this board)
Many divers doing decompression diving often use software to create ascent profiles that will minimize their time in the water performing decompression. From what I have been told, when you compare these profiles to what the computer on your wrist is saying, the "pre-cut" profiles often have you at a shallower depth sooner and for shorter times. When you follow your pre-cut plan, then you will violate the computer's recommendations and it will lock you out.
You also must remember that divers doing decompression diving will use different mixtures of EAN to both improve their safety margins and to reduce their deco times. Most of the computers out there are not capable of taking these gas switches into account. The only ones that I am aware of that can are the Vytec, Nitek3, and the VR3. These computers can be told that you've switched to a richer mix of EAN and recompute the ascent profile much like the desktop software packages can.
Single gas computers cannot understand that you've switched to a richer mixture and are now following a different "gameplan" to take advantage of the gas switch.
From my understanding, locking you out to gauge mode is the computer's way of telling you that you ignored what it told you and that for your own safety, you should not dive and it won't encourage you to dive by displaying NDL's or computing the ascent profile on future dives.
Just like I prefer having a conservative computer, I like the idea that my computer would lock out if I ignored what it was saying. In my view, by ignoring, I'm skating beyond the desired edge of safety that caused me to purchase the computer in the first place. In other words, I look upon locking out as a way of protecting me as a good thing.
Hopefully you will as well.
Now for some specifics about the Vytec.
The Vytec is a very new kid on the block with regards to mult-EANx gas diving. And I am just a "new" diver into this realm. So unfortunately, I am not yet qualified to answer questions on how the Vytec performs on this type of dive (but hope to be very soon).
Also I have not come across that many multi-EANx divers who have the Vytec and I can pick their brains.
But to answer your question, YES, the Vytec will lock you out to gauge mode if you ignore it's computer ascent profile and remain above it's computed ceiling for longer than 3 minutes.
Micro Bubble supression
One way of supressing Microbubbles is to follow the deep stop philosophy. I have used the simulator feature of the Vytec to discover how Deep Stops affected the ascent profile. What I discovered that as you stayed at 100, 90, 80, 70, etc feet for 1 minute, the ascent time would not increase any more (or would decrement very slowly) and the require deco ceiling would drift upwards toward 20 feet at a reasonable pace.
Unfortunately I don't own any of the deco software packages, so I can't compare to what they would compute.
Additionally, until we can do a head to head and controlled data gathering dive with both the SmartCom and the Vytec (and any other computer we want to add to mix), it would be difficult for any of us to comment on how the effectiveness of micro-bubble suppression compares between computers when using their displayed ascent profiles.
Battery Changes
The Vytec will allow you to change the battery yourself.
Gas Swithcing computers
As stated earlier, the only computers I am aware of that will allow you to indicate that you have switched breathing gasses are the Suunto Vytec, the Dive-Rite Nitek3, and the OMS/Delta P VR3.
