Jalisco is one of Mexico’s 31 states and is located on the southwest coast. It contains the tourist hub of Puerto Vallarta, which is a major port city on Bahía de Banderas (Banderas Bay). Bahía de Banderas, which faces the Pacific Ocean, is known for its beautiful beaches, tourist hotspots, and breeding humpback whales. Scuba diving is also the main attraction in this area. Various local dive shops offer certification courses and daily boat trips out to the offshore islands of Los Arcos and Las Marietas Islands. These islands have a rich biodiversity of marine flora and fauna due to their protected nature; Los Arcos, or Los Arcos de Mismaloya, is a National Marine Park, and the islands of Las Marietas are a protected wildlife sanctuary.

Liveaboard dive boats are not common for visiting dive sites within Puerto Vallarta and Bahía de Banderas, but there are some that leave from Puerto Vallarta to go to the Revillagigedo Archipelago (Socorro Islands). These islands, known for their shark encounters, are located about 650km offshore from Puerto Vallarta.

A series of impressive granite islands just offshore of the city of Mismaloya (southern part of Bahía de Banderas) are called “Los Arcos de Mismaloya”. These islands have been protected as a National Marine Park since 1984, and the underwater scenery makes divers feel like they are swimming in an aquarium.

At the northern part of the mouth of Bahía de Banderas is Las Marietas Islands, which are part of a protected wildlife sanctuary. Above the water, these islands are home to many endangered species of birds, and below the water, divers will come across numerous molluscs, echinoderms, nudibranchs, corals, sponges, and sea fans. It is not uncommon to see dolphins, giant manta rays, sea turtles, and humpback whales in this area as well.
Other popular dive sites in this region include “Majahuitas”, “La Corbeteña”, and “El Chimo”.