elan
Contributor
There are two school's of thought on that - my personal view is that there is every point in looking at the gauge.
For example, you may have forgotten to close the tank valve during the dive and a small freeflow has led to you having half a tank... so 6 cu ft of gas (the same size as my drysuit inflation bottle!). You are at 30m, is 6 cu ft enough to get you up? Do you end the dive, do you close the tank valve and go shallower to a depth where 6 cu ft is enough.... and so on.
Another example, you've bailed out and an ascent... a 13 cu ft is woefully small in my opinion. Is it better to be able to see the gauge and how fast it is dropping (so you can either vary your ascent rate or relax your breathing)or would you rather you just run out of gas half way up?
There is no definitive answer as to whether or not you should be able to see the gauge or not - you are correct, as am I. We make a choice to decide what to do - but simply telling someone what to isn't giving them the option of informed choice!
You have the valid point. Though I think 13 cuf is a bit on the small side.