It's all about task loading vs. familiarity.

I bet that like most ER folks you have great situational awareness at work, and are aware of everything that's going on in your department without having to think about it. If you are like me, during your first shifts in the ER it seemed like total chaos. Years later, it seems quite organized and easy to keep track of even when it's busy. The same thing will happen with your diving.

I have noticed that when I add to my task loading my situational awareness (and everything else) seems to suffer. The first few times I carried a stage bottle it seemed really awkward. Things that are usually effortless seemed difficult, and all I could think about was that great big awkward damned stage bottle. After a few dives with it, it was almost as if it wasn't there.

Mike