I'll probably run it no longer than 50-75 hours this time and see what I've got. It's a difficult call because it doesn't get much use. OTOH, arbitrarily changing it once a year seems like a waste. The annual oil change issue has been re-hashed ad nauseum here at BITOG. The most logical answer for justifying it is the life of the oil filter can in salt environments. No filter=no problem.
If I see moisture in the UOA or I get bored I'll shorten the drain interval. At a quart and a half I have enough oil on hand for the next 10 changes.
The answer to 80% of BITOG questions: Read the book, follow directions.
Changing oil is not maintenance. Maintenance is the science of inspecting equipment to find and fix things before they break.