John Mayer - Walt Grace's Submarine Test, January 1967
Tabbed by Axel Haumann (asehauDLM)

*NOTE* 
You can play it in Standard tuning if you want, but John plays it tuned down half step.
I've just tabbed the basic chords that John uses, I did not tab it note for note.
But with these videos below it should be quite easy for you to get into the rhythm/picking pattern.
John plays the chorus differently every time with many variations, so I've just tabbed a basic idea of it.

https://www.youtube.com/watch?feature=player_detailpage&v=7B30LMtIi-s#t=140
https://www.youtube.com/watch?v=kXY6rsxB1Xg&feature=player_detailpage#t=237
https://www.youtube.com/watch?v=vmnNKHwEQhg (he plays it in standard tuning)

But to help you here's the basic picking pattern which is used 
for all chords in the Pre-verse/Verse & Pre-Chorus.

|-------------------|                                                              
|---0----0----0-----|
|--7-7--7-7--7-7----|
|-5----5----5-------|
|-------------------|
|-------------------|


Intro:
!Play each chord twice!

|--7-7-----------7-7-------------|                        |---------------12---10-----------------|
|---8-8--10-10----8-8---10-10----|          4th time      |---------------------------------------|
|---------11-11-----------11-11--| 4x      ending with    |------------11---11--------------------|
|--------------------------------|         this instead   |------10/12------12--------------------|
|----------------7------9--------|         of 9/11/10     |---------------------------------------|
|--8-----10----------------------|                        |---------------------------------------|

Pre-Verse:

|-------------------|                                                              
|-0-------0---------|
|-7-------7---------|
|-5-------5---------|
|---7-5-7-----------|
|-------------------|

Verse:

|---------------------------------------|
|-0---0---------------0-----------------|
|-7---7----9----11----12---11----9------|
|-5---5----7----9-----9----9-----7------|
|---------------------------------------|
|-----7----8----10----0----10----8------|

Pre-Chorus:

|-------------------|
|-0-----------------|
|-5---0---0---------|
|-7---5---4---------|
|-----7---5---------|
|-------------------|

Chorus:

|---------------------------------------|
|--------3---------3--------3-----------|
|--------0---------0--------2-----------|
|--------0---------x---0h2--0-----------|
|--3-2---x-----2-3-3--------------------|
|------3-3---3--------------------------|

|-----------------------0---------------|
|------3---------3------1---3-----------|
|------0---------0------2---2-----------|
|------0---------x------2---0-----------|
|------x-----2-3-3---2--0---------------|
|--2-3-3---3----------------------------|

|------------------------------0--------|
|--------3---------3------3----2--------|
|--------0---------0------0----0--------|
|--------0---------x------x----2--------|
|--------x-----2-3-3---2--2----0--------|
|--2-3-3-3---3------------0-------------|

|---------------------------------------|
|---3--3---3--3------5---5---5---5------|
|---0--0---0--0------0---0---0---0------|
|---2--2---2--2------4---4---4---4------|
|--3---x--3---x-----5---5---5---5-------|
|-----3------3--------------------------|