This isn't 100% correct (particularly the bridge) but there aren't any other 
versions on here yet so I thought I'd give it a go...

Fm    C        B
Don't say it's over
Fm    C         B
Don't breathe a word
Dm        C     B
How was I so oblivious?
  Fm     Dm(?)         B
I didn't see how we got so deep down

(CHORUS:)
C                         B         Fm     C
  When we were walking on water for so long
                    B              Fm  C
I didn't notice the waves crashing over
B                   Fm
  I thought we were sailing somewhere
C                           B
  When did we start going under?

Fm, C, B x2

(2ND VERSE SAME AS 1ST) 
Now I see your colours
And now I hear your truths
I need something to pull us outta here
If we could get back up to the surface
Tell me could it be

(CHORUS)

Fm, C, B x2

(BRIDGE:)
Dm
   'Cause you made me wanna fight
B                             Fm 
  'Cause I found something to believe in
                    C
You made me who I am
            Dm
And it's so hard to see how
      B
We're so deep down

(CHORUS)