If he left home as a little kid, semi-educated, speaking only gaelic, then worked his way up to be a Captain, he did remarkably well.
The poetry of the time was inclined to be very stilted, with lots of very arty imagery but he must have been very highly thought of if he was:
"Hon. Bard to the Gaelic Society of New Zealand, and an honorable member of the Dunedin Pipe Band, he is also a member of the Burns Club, Dunedin and a worthy member of the Masonic Order."

I wonder who taught him - some friendly sailor on a long journey maybe? As an ex-teacher, I find it very hard to believe that someone with english as a second language, can rise to that level of literacy. I know James Cook worked his way up to be a Captain from lowly beginnings but he spoke english to begin with.
Very interesting people, our ancestors!
Robyn