I've puzzled over this line for years:

A howler o'er the toprail we steered sou'west away,

Steering "sou'west" from Portland doesn't get you to Nova Scotia, let along out of the harbor. However, a sou'west breeze would be very handy for sailing downeast to yarmouth, Nova Scotia.

What do you think, Kendall?

Cheerily,
Charley Noble