Mona Island diving

Puerto Rico’s remote island

Mona sits in the middle of the Mona Passage, roughly halfway between Puerto Rico and the Dominican Republic. It is a flat-topped limestone island ringed by cliffs, with sea caves along its shore and beaches on its south and west sides. Nobody lives there apart from the rangers of Puerto Rico’s Department of Natural and Environmental Resources (DRNA), which manages the island as a nature reserve.

Mona is often called the Galápagos of the Caribbean, for its isolation and its wildlife. It is home to the Mona ground iguana, found nowhere else, and its beaches are nesting grounds for sea turtles. Its caves hold traces of the island’s long history, from Taíno times to guano mining.

Why divers make the trip

Distance protects Mona’s reefs. With no towns, no rivers and very few visitors, the water around the island is known for being exceptionally clear. Dives explore reefs, walls and drop-offs around the island, with large sponges and coral formations, and a good chance of turtles, rays and big schools of fish, with sharks a possibility. Each trip is different, because the sites dived depend on wind and swell around the island.

Above all, Mona offers a feeling that is hard to find in the Caribbean today: diving somewhere that sees only a few boats a year.

How Mona trips work

Mona is not a day trip. The crossing from Puerto Rico’s west or southwest coast takes several hours across open water, and the Mona Passage can be rough. Trips usually last several days, either living aboard a charter boat or camping on the island with permission from DRNA.

• Permits. Visiting or camping on Mona needs permits from DRNA. Charter operators usually arrange this, but confirm before you book.
• Weather. Departures depend on sea conditions. Keep your dates flexible, and expect that trips may be postponed.
• Self-sufficiency. There are no shops or restaurants on Mona. Food, water and supplies come with you.
• Safety. Mona is hours from a hospital or recompression chamber. Dive conservatively and carry dive accident insurance.

Who it suits

Mona is for experienced divers who are comfortable with open-water conditions, possible current and remote diving, and who don’t mind basic comforts. Several days in a row of multiple dives means planning your no-decompression limits and surface intervals carefully. If you are building up to Mona, a Desecheo Island day trip is the best rehearsal: same passage, same kind of open water, home by dinner.

Life on a Mona trip

Days on a Mona trip follow the sun and the sea. Expect early starts, two or three dives a day when conditions allow, and long surface intervals spent on the boat or ashore at camp. Evenings are dark and quiet, with no town lights for miles. Many divers say the time out of the water, walking the beaches or watching iguanas, is as memorable as the diving itself.

Planning your expedition

Ask operators how many divers they take, what the boat or camp setup is, how they handle permits and what happens if the weather turns. Bring a surface marker buoy, a dive light, a backup mask and seasickness remedies, and take a look at the Puerto Rico dive gear checklist for the rest. Respect the reserve: take nothing, leave nothing and follow the rangers’ instructions about where you can walk and camp.

Rules and access for Mona can change, so check the current requirements with DRNA and your operator when you plan. For the bigger picture, see the Puerto Rico dive sites overview.