We sailed Mariner last year, and at that time, entertainment aboard was very good to excellent. Be sure to catch the ice show. It's a little bit of trouble to get the tickets, but well worth the effort. Big shows were very very good too, (although this ship had at that time the only two overweight female dancers I've ever seen aboard ship). Still, the shows were not to be missed. Piano bar and all the other offerings were very good. Even the karaoke was good. They had a "Mariner Idol" show or something like that toward the end of the cruise, and that too was lots of fun. Bottom line,,,,you won't be disappointed.