Everything about Parque Nacional Coiba is big. It’s one of the largest marine parks in the world. The island at the center of the park, Coiba (pronounced “COY-bah”), is Panama’s largest—a massive 493 square kilometers.

It has the second-largest coral reef in the eastern Pacific Ocean. And the waters are filled with big fish—very big fish, as in orcas, dolphins, humpback whales, whale sharks, manta rays, barracudas, amberjack, big snappers, three kinds of marlin, moray eels, and white-tip, hammerhead, and tiger sharks.

A total of 760 species of fish and 33 species of shark have been recorded. Sharks and mantas are plentiful, and there’s a decent chance of coming face to face with a sea turtle.

Visibility can be unpredictable, but even on “bad” days one is likely to see some impressive creatures. The diving here has been described as a cross between diving off the Galapagos Islands in Ecuador and diving off the Cocos Islands in Costa Rica.

Parque Nacional Coiba became even larger in 2004 when Panama enacted a law that raised its status and nearly doubled its area, to 430,821 hectares. Besides Coiba, the park includes the comparatively tiny (242-hectare) island of Coibita just off its northeast tip, the 20-square-kilometer island of Jicarón, the Islas Contreras, and 35 other islands and their surrounding waters, mangroves, and coral reefs. UNESCO declared it a World Heritage Site in 2005.

Coiba itself is still mainly covered in virgin forest—it’s reportedly 85 percent intact—though there has been some deforestation and forest disruption. Rare moist tropical forest is the most common vegetation.

As on most islands, there isn’t a huge diversity of animal species on Coiba itself, but there are at least 36 species of mammals, including howler monkeys, and dozens of amphibians and reptiles, including the deadly fer-de-lance snake.

You’re much more likely to come across beautiful birds, however, of which there are about 150 known species. Coiba is just about the last stand in Panama of the gorgeous scarlet macaw, which are concentrated in an area called Barco Quebrado. Other impressive birds common on Coiba include the bicolored hawk and the enormous king vulture.

Coiba also has several endemic species, including the Coiba spinetail (a bird—Cranioleuca dissita), Coiba agouti (Dasyprocta coibensi), and a local variety of howler monkey (Alouatta palliata coibensis).

Coiba attracts visitors largely on the strength of its world-class diving and deep-sea fishing. But the impact of human pressures, including the appearance of commercial fishing vessels that trawl these waters illegally, is beginning to mount.

Two things have so far kept nature more or less intact on and around Coiba: It’s quite remote and hard to get to, and from 1919 to 2004 it was the home of a Devil’s Island–style penal colony with convicted murderers, rapists, and other serious criminals. Prisoners were confined to a series of colonies around the massive island, but they were not locked in. Instead, guards locked themselves in their quarters with their guns at night. The island jungle and shark-filled ocean kept prisoners from straying too far.

Naturally, a place such as this inspires endless stories, some of which may even be true. There’s a legend, for instance, about the “mud man,” a runaway prisoner who roamed the island, covered in mud. He was said to steal up on other prisoners and strangle them to death, a “mercy killing” accompanied by whispered apologies.

The prison camp, along with its legacy of horror and misery, has been slowly phased out in recent years. Officially, the last 25 prisoners were removed from the island in 2004, but as late as 2008 a few guards and model prisoners were reportedly left behind to maintain the area.

For years there has been talk of building “low-impact” tourist developments in the park, but little has happened so far. Conservationists and subsistence fishermen continue to combat attempts to allow commercial fishing and other exploitation of the park’s resources. And there is still concern that commercial tuna boats are illegally using massive nets to fish the waters within the park limits, damaging fragile ecosystems. One hopes that common sense and long-term self-interest will prevail. Losing this Garden of Eden would be a tragedy for Panama and the world.

The island of Coiba is still relatively little known even by scientists. It’s hilly in the center and crisscrossed by many rivers, including the 20-kilometer Río Negro. But because of the penal colony, access to the island itself is only now loosening up. Most visitors only come ashore in the area around an ANAM field station on the northeast tip of the island, which still has the only guest accommodations. However, tour operators are increasingly venturing to Bahía Damas, on the east side of the island, to visit the spooky ruins of the penal colony and dive among spectacular coral reefs.

Getting to Parque Nacional Coiba

There’s a landing strip on Coiba, but only charter flights make the trip. Nearly everyone comes by boat.

Playa Santa Catalina is emerging as the primary gateway to Parque Nacional Coiba. It takes about 90 minutes by fast boat to get to the island from there. Some folks come out from Puerto Mutis, Santiago’s port, which is much closer to Panama City but a longer boat ride: 2–3 hours, depending on the boat. Other trips originate from Pedregal (David’s port).

Wherever the starting point, be careful whom you travel with. The trip is on open ocean that can quickly turn rough. I don’t advise striking a bargain deal with a local fisherman for this trip, as you’ll be riding in a small boat that probably won’t have a backup motor, life jackets, or a radio. One of these boats goes adrift at sea every month.

Even if you make it, you won’t be able to do much more than snorkel (with your own gear) from these boats. It’s better to go with an experienced, safety-conscious tour operator with a substantial boat and good equipment.