A quick trip to Norweigian or Princess cruise line website will give you an idea of the level of entertainment experience you can expect onboard ship.
As far as fishing goes, booking a fishing excursion while in port is usually an option.
I spent my last vacation snorkeling in the Pacific, kayaking up a river, hiking in a rain forest, splashing under a waterfall, horseback riding along a beach, and riding in a helicopter.
Now that's entertainment.