Whale season in Mexico (Sea of Cortez ) runs from January to March so you will not be there at a good time for Whales. The Huana Coa Canopy Adventure is a zip line tour with 9 ziplines. I haven't tried that one but it sounds fun.
In Cabo San Lucas I enjoyed an excusion called Sea Trek Helmet Dive
After the excusion I enjoy the beach. You can see my photo gallery. http://www.cruisemates.com/gallery/view.php?id=3459
I have never swan with the dolphins but you can also do that in Cabo this excusion is called Cabo Dolphins
For PV we did hideaway at las caletas
it was relaxing. Here is the description from Princess website:
"Only accessible by sea, board a catamaran for the approximately one-hour trip to secluded Las Caletas Cove, this natural paradise stands out backdrop of lush green forests in an secluded cove just south of Puerto Vallarta. When you arrive at Las Caletas, you can choose between pure relaxation or gentle exploration in the unspoiled natural setting of this tropical beach hideaway. If relaxing is on your personal agenda, you can kick-back on the beach, relax in the shade on a comfortable hammock, or indulge in a therapeutic body massage or facial at our hilltop Spa Center. Throughout the day, there are bilingual eco-guides offer snorkeling, kayaking tours, yoga class and clay modeling or take a Paella cooking lesson; discover Las Caletas' prolific flora and bird life on a free guided nature walk through the jungle, orchid gardens and interactive parrot center, or explore the natural amphitheater and the Mayan Pyramid hidden in the forest. A buffet lunch with beverages will be served. Spa services are also available for purchase. "