Accepted: If a movie involves a bisexual character refering to himself as "half-gay", it is most likely trying to be funny.
Accepted: If a movie involves Jeff Goldblum, it is funny whether it is trying to be funny or not.
Conclusion: "The Life Aquatic" is primarily a comedy.
My major problem with "The Life Aquatic" was that it was trying to be too many things at once. Almost any given sequence was entertaining in some form or another but... it was as though all the pieces did not come together as a whole.
However, for me, that isn't much of a problem. "Armeggedon" did one thing, did it exactly as it wanted to and was a completely terrible movie. "Titanic" very similar.
Aquatic... wants to be a screwball comedy about how dumb smart people are, sometimes... and it wants to be a whistful meditation on reality and magic and the human condition... and in places, it's almost an action movie, in places completely sincere, in places seemingly entirely ironic.
I think that's why it improves with multiple viewing and on DVD where... you can sort of look at each thread of the film and appreciate it without necessarily being overwhelmed by how those beautiful threads don't always weave together.