Basically, Lewis plays it using 2 chords again and again. Learned this off of his music video.
(Kinda mute it on the first verse)
Standard tuning, no capo 

Sink or swim, hold your breath and just dive right in
e |----0--0--0--0--0--0---|
b |----1--1--1--1--1--1---|
g |----0--0--0--0--0--0---|     2x
d |----2--2--2--2--2--2---|
a |----3--3--3--3--3--3---|
e |----3--3--3--3--3--3---|

*instrumental*
e |----0--0--0--0--0--0---|
b |----1--1--1--1--1--1---|
g |----2--2--2--2--2--2---|      2x
d |----3--3--3--3--3--3---|
a |----3--3--3--3--3--3---|
e |----0--0--0--0--0--0---|

Ride the wave, just, ride the wave far from where we came
e |----0--0--0--0--0--0---|
b |----1--1--1--1--1--1---|
g |----0--0--0--0--0--0---|     2x
d |----2--2--2--2--2--2---|
a |----3--3--3--3--3--3---|
e |----3--3--3--3--3--3---|