"For those that don't know, GAUGE is tech diving where you intentionally ignore all these safety limits and dive as deep as you want, as long as you want. You may enter deco, you may not, but the computer doesn't harrass you with safety stops, or count down your no-deco dive time, or really much of anything except give you depth, ascent rate, and dive time - all very useful stuff mind you, but not what you want when you're trying to keep from going into a deco dive or trying to maintain your 3 minute safety stop (or any additional time you might incur if you happen to have gone into a deco dive)."
This is completely false. Gauge mode is used any time you only need the required info to back up another computer or to provide the necessary information to follow the dive plan you should always do regardless of whether you use a computer or not. Relying on a computer to tell you when your NDL's are up, when to ascend, when to do a safety stop and for how long, and to prevent you from going into deco is a good way to get hurt. Your brain tells you all those things based on the plan you should come up with and the gauge mode provides the info needed to follow that plan. You do not need a computer to do recreational dives and in fact I recommend new divers not get one. Just for the reasons seen here. Too much reliance on it. It promotes what I consider to be reckless behavior on the part of the new diver. I want new divers to know how much time they have and decide for themselves when it's time to come up. Not wait on a computer to tell them.
There was no reason you could not have used the gauge mode to do the entire dive as a new diver. Divers are shown how to plan dives, monitor ascent rates, and keep track of their NDL's for a given depth. Or they should be even if learning with a computer. That would just be common sense to most divers. Computers fail. A watch and depth gauge and tables as back up is all that is needed to finish the dive and plan subsequent ones.
And it not a matter of experience at this level. It's about having the basic information passed on to you to allow you to deal with situations like this. A dead comp or one in gauge mode is no reason for a diver to cancel any subsequent dives unless the NDL's have been exceeded. It may require a longer surface interval than was planned for but no reason to stay out of the water for 2 days.
And one other thing. If this was a planned deep dive as part of course I am very dismayed to see that it appears it was not really planned. It seems like the plan was go down to 90 feet, watch til the computer says it's time to go up, and then do so. What was the gas management plan? What was the test or task to check for narcosis? What was the contingency plan? What did the instructor say about this episode? Did you have a written plan and back up method of following it?
