The often recommended 100hrs ODI (Oil drain interval) seemed a bit nuts for an ocean voyage by motor-sailer where the motor
is run for long periods in a dust free environment
and very few cold starts. Just like long distance highway trucking.
This article suggests I'm right.
Fig. 3 says ODI ranging from 18,000 miles to 40,000 miles.
Figure 6 paints a simple picture which puts the motor-sailer ODI at 400 hours and no mid-ocean oil change
Optimizing Oil Change Intervals in Heavy-Duty Vehicles
Of course there will be day sailers whose engines mostly run cold and would do better with 50hrs ODI