Things to Do in the Rosario Islands, Colombia

The Rosario Islands are a national park archipelago of 27 coral islands 35 km southwest of Cartagena. Most people arrive on a day trip, which is enough to understand the appeal - turquoise water, active coral reef, white sand, and the low-key atmosphere of a group of small islands that has been protected from development by its national park status. But if you have more time, the islands offer enough to fill two or three days without repeating yourself.

Snorkelling the Coral Reef

This is the main event for most visitors, and the reef here genuinely delivers. The Rosario archipelago sits within the Parque Nacional Natural Corales del Rosario y de San Bernardo, which means commercial fishing is prohibited and the coral has had time to recover from older damage. Elkhorn coral, brain coral, and sea fans are common at depths of 3–8 metres, easily accessible with a mask and fins. Larger reef systems extend to 15–25 metres for certified divers.

Where to snorkel independently: The waters around Isla del Rosario (the specific small island) and the northwest side of Isla Grande have the highest concentration of reef. Hire a local fisherman with a panga to drop you at the reef edge for approximately COP 20,000–40,000 per person - this gets you onto better coral than the crowded spots near the main lancha docks.

Guided snorkel tours from Cartagena: Most day tour operators include a 30–45-minute snorkel stop in their circuits. The guides know where to find sea turtles, which regularly congregate near the reef - a serious upgrade over solo exploration. Tours with snorkel included: approximately COP 130,000–180,000 per person.

Equipment rental: Available at several operators on Isla Grande - masks, fins, and snorkel vest for approximately COP 20,000–30,000 per day as of 2026. Bring your own if you’re particular about fit.

Scuba Diving

The Rosario reef offers Colombia’s most accessible Caribbean diving. Rosario Divers, based on Isla Grande, runs discovery dives for non-certified divers at approximately COP 450,000 per person and PADI Open Water courses for approximately COP 1,200,000 as of 2026. More experienced divers can access deeper sites at 20–30 metres where reef sharks and barracuda are occasional sightings during the December–April dry season when visibility reaches 15 metres or more.

The Oceanario (Marine Rescue Centre)

Located on a small atoll within the archipelago, the Oceanario Islas del Rosario is an aquarium-cum-rescue-centre operating since 1977. It houses sea turtles undergoing rehabilitation, nurse sharks, rays, and around 60 species of Caribbean fish. Unlike a typical tourist aquarium, the animals here are largely rescues from bycatch or injury, which gives the experience a different moral weight.

Entry: approximately COP 25,000–35,000 as of 2026 for independent visitors (most day tours include entry). The Oceanario is included in virtually every organized day trip from Cartagena.

Glass-Bottom Boat Tours

For non-swimmers or families with young children, glass-bottom boat tours offer a window into the reef without getting wet. Operators at Isla Grande rent these for approximately COP 15,000–25,000 per person for a 30-minute circuit over the main reef formations. The clarity of the water means the views are genuinely worth the modest cost.

Kayaking the Mangroves

The eastern side of Isla Grande borders a mangrove channel running between the islands. Kayak rentals are available from several operators on the island for approximately COP 20,000–30,000 per hour. The mangrove tunnels are navigable at high tide and offer shade, wildlife (frigatebirds, herons, hermit crabs), and a complete change of pace from the open-water beach experience.

Sunset Catamaran Cruises

A small number of Cartagena operators run evening catamaran trips that stop at the outer Rosario Islands at sunset before returning to port. These are distinct from the daytime tour circuit - smaller groups, drinks included, and timed to catch the light changing over the reef. Prices run approximately COP 180,000–280,000 per person as of 2026. Look for these on the main Cartagena tour booking desks near the Old City.

Island Hopping by Lancha

The islands are close enough to each other that you can hire a local boatman with a small motor canoe to take you between islands for COP 20,000–50,000 per trip. Isla del Rosario, Isla Grande, and several of the smaller uninhabited cays are all worth exploring at a pace the organised day tours don’t allow.

Hammock Time

Not everything needs to be organised. Isla Grande has several beach bars - La Playita and Finca Paraíso are two of the established names - where you can rent a hammock strung over the water for approximately COP 10,000–20,000 per hour, including a cold beer or coconut. This is the correct use of a Tuesday afternoon in the Rosario Islands.

Practical Tips

• National park entry fee: Approximately COP 28,000 per person (2026); usually paid at the Cartagena dock.
• Best conditions: December–April. Calmer seas, higher visibility. Avoid holiday weekends when the islands are packed.
• Cash only on the islands. ATMs are in Cartagena - withdraw before you leave.
• Reef-safe sunscreen only. Standard chemical sunscreens damage coral. Products with zinc oxide or titanium dioxide are the safe alternatives.