If I'm not mistaken the NCL ships dock over by the airport. This is NOT where you want to go looking for nightlife in Maui.
Kuki has recommended the BEST activity on Maui for evening entertainment (and dinner and unlimited drinks so designate a driver). Old Lahaina is hands down the best Luau in the islands by far. Make reservation in advance .
Lahaina town itself would be my next suggestion for an evening of entertainment. Many good restaurants at every price point along the main street in town as well as stores and galleries of every description.
Lahaina is definately where you want to spend your evening. However.
if you don't want to drive that far, try Mama's Fish House (make a reservation in advance) in Paela Town. North shore beach view, lovely grounds and best food in Hawaii (do bring a credit card that has a large limit on it). Their Mai Tai's are giant and excellent.