Here are the chords in THE SINGING ISLAND, compiled by Ewan MacColl and Peggy Seeger:

    Cm            Bb             Cm                        Bb
The Diamond is a ship, my lads, for the Davis Strait she's bound
       Cm             Bb    Cm       G7             Cm   
And the quay it is all garnished with bonnie lassies round
       Cm                Bb    Cm                Bb
Captain Thompson gives the order to sail the ocean wide
          Cm          Bb       Cm       G7               Cm
Where the sun it never sets, my lads, nor darkness dims the sky
       Cm    (Bb)    Cm
So it's cheer up, my lads, let your hearts never fail
                         Cm      Bb       Cm    Bb       Cm
While the bonnie ship The Diamond goes a-fishing for the whale