Ixtapa and Zihuatanejo are two places that share an airport. Ixtapa is a planned resort strip on a long open beach; Zihuatanejo is the fishing town around a sheltered bay six kilometres south, and it is the better base for everything on the water.
Diving and snorkelling work the rocky points and offshore pinnacles — Los Morros de Potosí is the serious one. Visibility is Pacific rather than Caribbean, so expect ten to thirty metres and schooling fish rather than coral. Humpback whales pass between December and March. Sport fishing out of Zihuatanejo is excellent and long-established, with sailfish the usual target.
Playa Las Gatas, across the bay and reachable only by water taxi from the municipal pier, has a stone breakwater said to have been built on the orders of a Tarascan king and now shelters the calmest swimming here. Playa La Ropa is the long sandy one; Playa Linda up at Ixtapa has the boat to Isla Ixtapa.
Turtle releases run on the beaches east of town in the nesting season, and the crocodile lagoon behind Playa Linda is worth a look.