Airship Guide

[Jashynvald]

Strictly speaking, SC01 is #0, and said offset continues until Diadem (Hard) appears in the list. SC23 is then #23, and SC24 is #24. There does not appear to be any additional sectors beyond that.

While I now have 23 and 24 unlocked, I won't have a ship return for 13+ hours, so I unfortunately can't answer your other question :x

You can just check navigational charts on one of your airships without needing to recall it I thought.