Cartagena7 tours

Bioluminescent plankton

Bioluminescent plankton is a natural light show: microscopic organisms that flash blue whenever the water moves. Near Cartagena you see it in the Laguna Encantada on Barú island, and tours pair it with a beach day so you reach the lagoon right after dark.

What bioluminescent plankton is

What glows in the water are dinoflagellates: single-celled organisms that are part of the plankton, the tiny life that drifts at or near the ocean surface.

They make their own light through a chemical reaction, and any strong enough movement sets it off: a wave, a swimming fish, or your hand stirring the water. The flash comes less than 20 milliseconds after the trigger, so the glow appears the instant you move.

That is why the experience means getting in the water or stirring it: still, the plankton barely shows; in motion, it leaves trails of light around your body.

Source: Latz Laboratory, Scripps Institution of Oceanography (UC San Diego)

Where to see it near Cartagena

The spot is the Laguna Encantada (Enchanted Lagoon), also known as the Portonaito marsh, on Barú island, about 45 minutes from Cartagena. It is a mangrove-lined lagoon, no deeper than two to three meters, with water between 27 and 30 °C (81 to 86 °F).

You reach the lagoon by boat from the beaches of Barú. That is why every plankton tour spends the day in that area before the night activity: Playa Blanca, Playa Tranquila, Mambo Beach Club, or a Rosario Islands trip that ends on Barú.

Source: El Universal (Cartagena)

Which nights are best

The glow is faint, so it depends on how dark the night is. The Laguna Encantada lights up most on dark nights and around the new moon; under a full moon the glow loses contrast.

If your dates are flexible, check a moon calendar and aim for the days near the new moon. On the tours, the activity starts around 6:45 p.m., once it is fully dark.

Source: El Tiempo

What the tour is like

Most options are full-day trips: you leave Cartagena in the morning, spend the day at the beach, watch the sunset and do the plankton before heading back. The evening runs the same way on all of them:

Tour	Departure from Cartagena	What it adds to the plankton
Playa Blanca + Plankton	7:00 to 8:40 a.m., by neighborhood	Day at Playa Blanca, local-style lunch and sunset
Playa Tranquila VIP + Plankton	7:00 to 8:40 a.m., by neighborhood	Boat to Playa Tranquila, sunbeds and loungers, lunch
Playa Tranquila Deluxe + Plankton	7:00 to 8:40 a.m., by neighborhood	Breakfast, welcome cocktail, umbrella or hut, lunch
Sunset Plankton at Playa Tranquila	1:30 to 2:00 p.m.	Afternoon at a beach club and sunset; back at 8:00 p.m.
4 Islands Premium	Morning hotel pickup	Rosario Islands, snorkeling, Isla Cholón and lunch at Playa Tranquila
5 Islands VIP Free Shots + Plankton	7:00 to 8:00 a.m.	Bocachica, Isla Grande, Mambo Beach Club and sunset on Barú
Mambo Beach: raccoons, snorkeling and plankton	Morning, by pickup zone	Mangrove walk, snorkeling and Mambo Beach Club

Safety briefing before the activity, with a snack
Round-trip boat ride to the lagoon, around 6:45 p.m.
Instructors and life jackets throughout the activity
Return to Cartagena by road, between 7:30 and 8:00 p.m.

If you only want the plankton and not the beach day, Sunset Plankton is the shortest option: about six and a half hours from pickup to drop-off.

What to bring

Wear your swimsuit, since the activity is in the water
A towel and a change of dry clothes for the ride back
Sunscreen for the beach day
Cash for drinks or activities your tour does not include
On the 5 Islands tour: cash for the port tax and the assistance insurance, paid separately at the dock

Check whether your tour lets you bring food: Playa Blanca + Plankton and Playa Tranquila VIP do not allow outside food or drinks; Sunset Plankton does.

Frequently asked questions

What time do you see the plankton?

The activity starts around 6:45 p.m., after dark. You are back in Cartagena between 7:30 and 8:00 p.m.

Do I need to know how to swim?

No. The activity takes place in shallow water, guided, with instructors and life jackets.

Can children come?

Yes. On most tours children pay the adult rate. On 4 Islands Premium, kids under 3 go free and must be supervised at all times.

Does the plankton glow the same every night?

No. It shows best on dark nights around the new moon; under a full moon the glow is harder to see.

Where is the Laguna Encantada?

On Barú island, about 45 minutes from Cartagena. You get there by boat from the Barú beaches, and that ride is included in the tours.

Should I book ahead?

Yes. Groups are capped at 20 people and spots fill up in high season.

Go with us

These are the tours we run to Bioluminescent plankton. Prices come live from our catalog, in Colombian pesos (COP) per adult. Tour pages are in Spanish; write to us on WhatsApp for anything you need.