Just as a matter of interest did any of ex. 2nd mates on here ever keep their "courses and distances" book that contained all those passages that you had worked out using rhumb line or great circle sailings?
I kept mine up to about 10 years ago when it got lost when doing a loft clearance.
Once totted up the total miles I had steamed in 30 odd years and although I cannot remember the exact total it was certainly in the million bracket.
rgds
JA