WOOO!!!! First tab on here.
Although there are many variants in tabs iv'e seen, I have studied his playing on 
youtube ( <3 Johnny )
and am pretty confident this is how it goes, enjoy.

Intro:

E|-----0--0--------------0--0-----1--1--|
B|-----1--1-----0--0-----1--1-----1--1--|
G|-----0--0-----0--0-----0--0-----2--2--|
D|-----2--2-----0--0-----2--2-----3--3--|
A|--3-----------2--2--3-----------------|
E|-----------3-----------------1--------|

|-----0--0----------------0--0----------------1--1-----1--1--|--|
|-----1--1----------------1--1----------------1--1-----1--1--|--|
|-----0--0----------------2--2--0h2--0--------2--2-----2--2--|--|
|-----2--2----------0-----2--2----------0-----3--3-----3--3--|--|
|--3-----------0h2-----0----------------------------3--------|--|
|-----------3------------------------------1-----------------|--|

So something like that for the strumming pattern also (1 bass pluck then 2 strums)

Verse:
 C         G             F
All that I have is a river
     Am                 E
The river is always my home
      C         F        Am           F
Lord, take me away for I just cannot stay
        C          G           F
Or I'll sink in my skin and my bones


Chorus:
    C        G           C         F
The water sustains me without even trying
    C            G            Am
The water can't drown me, I'm done
        F      C
With my dyy...ing


Interlude:
C G C C
(just holds top 2 strings for G here)


 C         G             F
Please help me build a small boat
     Am                 E
One that?ll ride on the flow
       C            F
Where the river runs deep
       Am           F
And the larger fish creep
    C          G           F
I'm glad of what keeps me afloat


    C        G           C         F
The water sustains me without even trying
    C            G            Am
The water can't drown me, I'm done
        F      C
With my dyy...ing

Interlude
C G C C


     C         G       F
Now deeper the water I sail
     Am                    E
And faster the current I'm in
      C           F
That each night brings the stars
        Am           F
And the song in my heart
      C             G           F
Is a tune for the journeyman's tale


    C        G           C         F
The water sustains me without even trying
    C            G            Am
The water can't drown me, I'm done
        F      C
With my dyy...ing


Bridge:
 E                            Am
Now the land that I knew is a dream
 E                                  Am
And the line on the distance grows faint
    C          Dm          C         Dm
So wide is my river, the horizon a sliver
     C          G          Am      F
The artist has run out of paint...


           C           G             F
Where the blue of the sea meets the sky
        Am                       E
And the big yellow sun leads me home
    C          F
I'm everywhere now
    Am        F
The way is a vow
       C            G             F
To the wind of each breath by and by


    C        G           C         F
The water sustains me without even trying
    C            G            Am
The water can't drown me, I'm done
        F      C
With my dyy...ing

Outro:
Played similar to intro (with the added hammer-ons on G, Am at end)

C G C F C G Am F C

Please correct me if I'm wrong but it you watch the Video you'll see
where the changes are that Iv'e made especially on the Bridge.
Here's the vid :(http://www.youtube.com/watch?v=a4QQ7HYYdWw)