Maybe this one is better, still not sure about Am7 though, thoughts?

V1:
Dm             F                C                         Bb       C                Dm
I must go down to the seas again, to the lonely sea and the sky
Bb                F                   Gm                   Am7
All I ask is a tall ship and a star to steer her by
                Bb                            F                               C               Dm
And the wheel’s kick and the wind’s song and the white sails’ shaking
            Dm                     C                        Am7   C       Dm
And a grey mist on the sea’s face, and a grey dawn breaking