How bad is it? It's near the bottom of the IMDB bottom 100 films list.
Should you see it? No.
Hard to believe this is the first Adam Sandler film on this blog (at least one more is coming), but while I find him tiresome after two minutes of schtick, his fans do not; I also think he can handle serious roles fairly well (I liked "Spanglish"). This film is not funny. It's about a stand-up comedian so bad he can't get hired on a cruise ship as an entertainer, so he works on it as a deckhand and waits for his big chance. A comedy about an unfunny comedian could be funny - Andy Kaufman's alter ego Tony Clifton almost worked that way, but this isn't funny. It's not even so bad it's badness becomes funny - it's not that good.