My (newish) dive buddy makes a good choice...

[TSandM]

It's better to avoid being in such a situation, but given that you were in it, good judgment was shown by all involved. It makes far better sense to share gas BEFORE anybody is out; that way, if there is a problem with separation, no one is without something to breathe. But it's also important to remember that, for the vast majority of dives, a safety stop is completely optional, so if there is a low on gas or other urgency, it is fine just to continue a nice, controlled ascent all the way to the big gas tank in the sky

 

[John_B]

To the excellent "rock bottom" advice above, I'd just add a recommendation to check your SPG every five minutes -- and to do it religiously.

I'd also add that, IMO, 15 dives is not enough experience for a 90 foot dive. One of the things taught (or that should be taught) in an AOW class's Deep Dive is how fast a diver goes through air at depth, and how much slower the brain processes that important piece of information. I'm not saying a new diver has to learn that in a class, but I'd like a newish diver to have learned that somewhere before attempting a dive below about 60 feet.

Regardless, great reaction to the situation, and a great thread for discussion!