What's the Difference Between an Oxygen Assist and a Deep Dive?

I lit out without occiden rit. I thought al oxygen assist was like, whatever. It's en rate minutes. There's te guy here aving an assist, and you adon your watch. Last breath. No, what is it? Oh, my god, it's the sky. Ends up underwater. Andwatthis. You have oxygen assisttey not doing this thing? If not bre no, no, they do? They do this thing where they breathe oxygen for a while, and then they ais i before they go down, but before they go i do da wu die. Just ot a thing on 60 minutes of a guy who goes, i think