Reasons why this movie is an awesome comedy

1. Great cast (many of which went on to become comedy/acting legends)
2. Kelsey Grammar and Rip Torn, 'nuff said
3. Memorable lines
4. Hilariously funny scenes, too many to mention here
5. Best way to get rid of a mean, bullying Second Officer ever
6. Best case of turning a rebellious trouble-maker into a decent member of the Navy.
7. Most interesting use of a running gag involving tattoos.
8. Funniest way to trick an enemy sub into thinking you're not a sub yourself.
9. Portrays the Navy in a positive, if silly and inaccurate light.
10. Best way to show that women in the Navy are tough and more than capable of putting up with a lot of crap from their fellow submariners.
11. Good story.
12. Great character development.
13. A good case for giving a guy who's had bad luck in the Navy a chance to prove himself.
14. Best case of a crew of misfits succeeding against all odds.

There's more, but that's what I can think of off the top of my head right now :)