Love a big ballad! The standard tune I keep hearing is "The Range of the Buffalo" which works well for scanning purposes. My tinkering suggestions is for this verse:

We found a small herd of seal we were about 3 hours out,
When a spring breeze from the southeast blew, in some it caused alarm,
On just a pleasant day as this, 16 years now gone by,
No weather eye had seen the change that raised many a mournful cry.

Changes:

We found a small herd of seal, we were 3 hours out,
When a spring breeze blew in from the southeast, in some it caused a doubt,
On just such a pleasant day, now 16 years gone by,
No weather eye had seen the change that raised many a mournful cry.