Puerto Vallarta and the Bahia de Banderas wrap Mexico's central Pacific coast with easy day-boat access to rock reefs, caverns, and offshore pinnacles. Divers base in Puerto Vallarta, Nuevo Vallarta, or Punta Mita, then hop to Los Arcos for shallow training dives and nudibranch hunting, push farther to El Morro for caves and pelagic chances, or head north to Islas Marietas for volcanic tunnels and reef fish. Winter brings humpback whales in the bay, while summer and early fall deliver the warmest water and often the clearest visibility. Topside, you get a walkable Malecon, jungle day trips, surf towns like Sayulita, and sunset sea turtle releases. The region rewards early starts, flexible planning around rainy season squalls, and respect for protected-area rules in Marietas and Los Arcos.