Coiba

Diving here is a day out of Santa Catalina, a small surf town at the end of a long road, and the boat ride is a real part of it — an hour or more each way in an open panga over water that can be flat or genuinely bouncy. Trips are usually two tanks with the surface interval spent ashore on a beach inside the park, so the day runs long even though the diving itself is undemanding. A handful of liveaboards work the same waters and the banks further offshore on longer schedules.

Sites divide by how far out they sit. Close in, around the main island and its islets, the ground is rock and hard coral in reasonably sheltered water, shallow enough to make a long, slow dive of it. Further out the rocks are bare, exposed and current-driven, and those dives are shorter, deeper and about whatever turns up out of the blue. Clarity varies a lot — this is a productive, plankton-fed stretch of the Pacific, and a cold layer can slide in mid-dive and take both the temperature and the view down with it.

That mix makes Coiba unusual for this coast. Most of the big-animal diving in the Eastern Tropical Pacific costs a multi-day ocean crossing; here it comes on a day trip, and what you trade for the convenience is consistency rather than scale. The format has its own limits — when the swell is up, the outer rocks are the first thing dropped from the plan and the day retreats inshore. Park fees are collected at the ranger station and are normally folded into the trip price.

What Coiba does not do is guarantee. The whale sharks, the hammerheads and the humpbacks are passing traffic rather than residents, and a week inside the right window can go by without producing any of them. The dependable part is what lives here: reef sharks, turtles and fish schools thick enough to close down the view. It is also a sensible place to log current dives before committing to one of the region's long offshore trips, where that experience is assumed rather than taught.