I guess most plausible theory is that admiral has a terminal disease or have very weak body, and that's why he doesn't "officially" become one. If he is seeing the fairies, then he should have the ability to become admiral.
But I at least wanted to see the real ocean.Whole bunch of fairy-sans, too.I started planning my escape from the hospital.Thinking that there was scant time left for me,There really was no way that I'd get approval to go out, you see.So you did love the ocean too then, Commander!There were base-related facilities there as as well, after all.And once I started to notice them, they were everywhere.Perhaps it was... imprinted into my subconscious in a way."See Naples and die"... I would never talk of such extravagance.
An old saying, from the idea that the city of Naples was so beautiful that once you have seen it, you can die peacefully - because nothing else will match it.