The shore excursions were great and the way to explore.

Here are the ones we took.

Acapulco
City Tour and Cliff Divers. A must if you haven't seen them. 3:30 hours

Zihuatanejo
Ixtapa Resort Tour. Takes you to the modern hotels and condos over the hill from Zihuatanejo. Stops for shopping. 3:45 hours

Puerto Vallarta 
Mismaloya Beach and city. Excellent. You see and walk the town's waterfront and then drive to the spot where "Night of the Iguana" was filmed. Free drink at a nice restaurant overlooking Mismaloya. 3:30 hours.

Mazatlan and Copala
The second cruise has a tour to Copala from Mazatlan. 

Reserve your tours early at the tour desk. Some fill up fast.