The next zone of Cataclysm which is both most beautiful and most hated is of course Vash’jir, a piece of sea bottom not far from Stormwind. As you probably waited for Azshara – you won’t meet her here. Instead you are involved into a desperate survival questline and help Neptulon and earth shamans to fight the old gods’ influence.
You probably know that Blizzard wanted to introduce a whole underwater expansion. In the web-series “The Guild” the idea was actually put in use. But IRL it would be of course horrible. We are creatures who are used to walk and fight on the solid ground, we don’t have any fins and fishtails, so almost every fight here is a disaster as you must also consider depth direction. And while they could design underwater sunken palaces with some air (as they did with caves), constant feeling of huge mass of water over your head is really pressing too much, and you’re not only claustrophobic but always wonder if you choke in the next moment despite all the spells :=)
So, on to the questline. Rottenshield and Chitsuro are sent to the respective havens of Stormwind and Orgrimmar to join the Horde and Alliance parties. A new set of isles is risen from the depths near Stormwind, and while Horde sees them as an excelent attacking ground, a base to be established there, Alliance obviously doesn’t want them to do so.
Frankly speaking, the isles are actually too small to prepare a massive invasion on the most fortified and populated city, but neither of the sides cares and you join the ship.
When you arrive ar the harbors, you are supposed to wait long, until a mercenary pirate ship arrives. Meanwhile, you may talk to grunts and footmen and admire the view.
Then the ships arrive, and you are trapped there along with some stupid mercenaries (some of them are just crazy) and stinking soldiers, who smell like barracks. And seasickness added.
Nazgrim and Taylor on our approach say some short speech, like “we crush the enemy”!
Not a big difference between Horde and Alliance actually here.
Then you are attacked by Kraken, and that’s the end of your journey.
Would be cool if the journey ended here, and you wake in a capital tavern. But no, it actually happens. You are not drowned, and all your mates are attacked and stolen by Naga. Luckily (or not), Erunak Stonespeaker (better it be Tidespeaker) launches some fire, blasts them and takes you into the sunken ships where you can breathe a bit.
When you have a spell at your disposal, you can at last go and do some activities like collecting armor for your troops. Don’t ask me how they swing the heavy swords underwater. You don’t ask also how Salash the Orc Hunter shot everyone here, do you? That’s one more confusing thing about sea. You don’t notice it in the occasional pond-river quests, but you can’t keep wondering about using a crossbow in the sea for many hours.

Erunak walked around the corner to pee, it seems, so you’re kidnapped again.
When Erunak zips his fly, he finds out that all the boys and girls are stolen and he chases us until he blasts the kidnappers to pieces, phew.
Then you are at last allowed to do some activities.
Like:

Oh, and if you have troubles finding your base or simply a place to breathe a bit – just look for these orange-purple sea flowers. Just don’t mess it up and enter Alliance or Horde cave (at least they have flags there).
More activities include:
Oh, and these big shells are actually the coolest looking demigods. Sadly, they are almost dead by your arrival. But at least you can run inside with some air to breathe and bring some revenge upon Naga.
That’s a perfect way to an epic Throne of Tides. Guess what you do there? *sigh* Fighting Naga of course.
As if you didn’t have enough Naga in the recent hours, you also have a big opportunity to watch a Discovery program through an ancient blade about… NAGA!
Finally they allow you to breathe a bit. It’s not only going to the surface, it’s launching you high up like a rocket. Obviously Blizzard were also tired of questing underwater, so this launch fully covers your big joy about going up! And you thought you will never do it and spend the rest of your days here, cut from the other world.
Before you can go to the faction ships, you MUST make the coolest selfie ever in the middle of the ocean.

And then you go to the ships.
Btw, there are shamans who offer you a new task – NOT UNDERWATER, so you can quit the zone at once! Despite that, I strongly advise to participate in a giant squid hunt on board of goblin and gnome submarines!

When Rottenshield departed, she failed to go into the submarine itself before the doors were locked, so she saw all the event with her own eyes! (actually you don’t see a thing from the submarine guts).

But the insides of the submarines are actually very cool by themselves, including the brave captains.
Then you end up in a one more cave, and have to…

At this point you should procede and finish the zone (little left) – then you will have a quest in underwater dungeon. But frankly it’s grinding up to the end.
Being the most beautiful zone in Cataclysm (along with Uldum) and certain highlights, Vash’jir grows more and more tiresome by the end. So you’re happy to quit it. Hope the idea of an underwater world never pops up in WoW again.