I have madea few deliveries from Sydney to Hobart. Its about 600nm, and it divides pretty neatly into 3 parts:
1. Sydney to Gabo Island (NSW Coast)
2. Gabo Island to Eddystone (Bass Strait)
3. Eddystone Point to Hobart (Tassie Coast)
Each section is about 200nm, give or take.
For that particular trip, the middle section always seems to be longest, and the last section the shortest. I guess in Bass Strait, I have no landmarks to "tick off". Whereas going down the Tassie Coast, I know every point, bay and town.