I've had the same problem along with many others. There was about 10 druids there yesterday when I was and none of us could find it. All internet searches showed the chest and air bubbles should be due west of the wrecked boat on the coast but nothing is there. I've upvoted your bug report.
Had done it today, it`s on underwater piece of earth, you can see it in videos like that: https://www.youtube.com/watch?v=Kw8tzeN0I2I
The problem is, this underwater bubbles that supose to restore underwater breath are not working in our server, which means you will die near this chest, and resurection point is on barrens. So the tactic is - go underwater until you have half of breathe, if you see chest - go for it, otherwise - go up and wait till it will appear.
Pretty hardcore quest, had done it in first try, was lucky.
Lovely thank you hope they can look into it. i have decided to wait up a bit for it and get some water breathing elixirs when i can make them and try again :) thanks for the replies <3
I've done the quest now, it's not bugged it's just in a different location than it's meant to be. You need to swim out further west from the coast into the fatigue zone, somewhere around 31,29 i think, forget exact coords. I died just as I looted it so you need to be precise when you dive down.
I died, but i got it done. Just swim until you are directly above the air vents (that i can confirm are 100% broken) and grab the item as soon as you are in range too. You will die. Period. But it is not hard to complete. Just have to deal with rez sickness after.
Tauren Druids are bugged when in water, you need to jump all the time while swimming in order to keep your Breath at its top bar. If you just swim, its decreasing like you are diving. Will check bugtracker and bump this.
What I did was waited until I got the Underwater breathing item(Or get a Warlock to buff you with it) from the Eels quest in Zangarmarsh, used my last charge to give myself water breathing.
You will die to the fatigue zone no matter what so make sure you start from near the ocean floor just outside the fatigue zone and swim straight to it.