Have you tried returning to port and seeing what kind of renown score you have? In SH3 you can return to port without objectives accomplished and still you get credit for what you did. You just do not get the additional points for your objective. I believe it works the same way here. If so, I don't see why that should be irritating. I have never waited to be called back. I am the captain of my boat and will return when I deem necessary. The Admiral has always backed me up.
Success is how many ships you send to the bottom, not whether you occupied a certain empty spot in the ocean for however many hours you need to get credit. How close to the star do you have to remain for how many hours to get credit in SH4 anyway?