User blog comment:WonderfulUnicorn/New admiral prediction (home-made character)/@comment-5962458-20130212210735/@comment-4605926-20130212220828

I don't really think the admirals are strictly assigned to bases around the world if any, it's most likely going to be the Marine Headquarters. I'm also kinda sure they each have their own missions, they don't go out to sea to do whatever they feel like doing that particular day. Either missions they assign themselves and others to, or missions assigned to them by higher officials. Remember, this is their job, as much high ranked as they may be, they still have to finish their assignments. Pirates do what they want, or perhaps pirate captains as their subordinates have their assignments as well. Yonkos even more so, as pretty much nobody can oppose them. This is why Luffy wants to be the "Pirate King".