
It will tak several tries, but it will work

The firs part is taken from jabbo:
This isn't much of a foolproof strategy, but it kinda helps. There are four switches each controlling the four gates around them, and these main four switches are arranged in a diamond, which you start at the bottom of.
..1..
2..3
..4..
..X..
..Y..
You start at the X.
At the very beginning, swim up, ignore the first set of switches you come to (set 4), and activate either set 2 or set 3 as quickly as possible. Then, again as quickly as possible, open up the one of the side gates and activate the other so that both set 2 and set 3 are activated. Then go back and activate set 4. Then open the upper door of set 4. Then head back to the first room (Y). The go and open upper door of set 3 and quickly close the doors to set 4. Head back to the room. At this point just lure the monsters into the "room" you made with the doors. And then open left door of set 4 and swim to the top

Hope I helped.