I have a good oil change setup, so it really isn't that difficult.

The biggest issue is ordering the oil filters well in advance.

Since I really do focus on sailing, it is unlikely for me to get enough engine hours in a year. I can get to open water in about 10-15 minutes. And I often sail right to the inner harbor. (might just start sailing in... just to keep sharp at it).

So I have a tendency to only run the engine in 10-15 minute spurts. An annual change is probably a good idea.