Mazatlan is located on the Pacific coast of Mexico, across the Gulf of California from Cabo San Lucas. Mexican Riviera cruises visit the port.
The best time to visit Mazatlan is anytime other than summer. Which is fine because the cruises from San Diego are in the cool weather months.
Beaches are a main attraction, of course. Walk along the Malecon to see the art works. Try Playa Cerritos and relax under a thatch umbrella. You can rent wave runners there too. Playa Olas Altas offers a boardwalk for strolling, food, drink, and waves for surfing. Deer Island is a place to kayak, swim in calm water, or have fun on a banana boat.
Take an excursion to the picturesque little town of Copala. The colonial architecture is beautiful and there are scenic views all around.