Cabo San Lucas is a famous cruise destination in Mexico. Mexican Riviera cruises go there. It is located on the southern end of the Baja peninsula.
The beaches on the Sea of Cortez are quite calm, but surfers ride the waves at Zipper's and other breaks. Surfing lessons are available for the adventurous.
Scuba diving and snorkeling are very good in the area. Jacques Cousteau called the Sea of Cortez "the world's aquarium". Hop on a fast boat to the top dive spots. Cabo Pulmo National Marine Park has 3 living reefs and the only hard coral reef in North America.
The video below is about diving in Cabo. It looks like great fun.