Board a sunset cruise from Puntarenas to Isla San Lucas, swim in warm, natural-pool waters and watch bioluminescent plankton flare with each movement. This 4–5 hour small-group tour combines calm snorkeling, birdwatching around islets, and a guided nighttime light show.
More ways to explore the area's outdoor wonders
The boat slips away from Puntarenas as the sun bleeds orange behind the mainland—salt on your lips, a scattered flock of seabirds wheeling around low islets that seem to sleep in the shallow light. You feel the current nudging the hull, the water around the bow glittering like a spilled galaxy; by the time the small beach on Isla San Lucas appears, the day has given its last warm breath and the real show begins.
Difficulty
easy
Duration
4–5 hours
Fitness Level
Suitable for most fitness levels; able to climb into a small boat and swim/snorkel in calm water.
Wildlife
History
Isla San Lucas was once the site of a penal colony; remnants and local stories of that era remain part of the island’s identity.
Conservation
Bioluminescent displays are fragile—guides discourage soaps, flash photography and touching organisms; responsible tour practices help protect the local marine environment.
Reserve your spot on the Bioluminescence Cocos Tours today and enjoy a trusted, highly rated experience designed to help you make the most of your adventure.
Bring a waterproof phone case
Protect your device—photos are tempting but use a waterproof sleeve to capture the glow without risking damage.
Take motion-sickness meds ahead of time
Even short open-water crossings can be choppy at sunset; take prevention 30–60 minutes before departure if you’re sensitive.
Avoid flash photography
Flashes disrupt the bioluminescence and wildlife—use your device on low-light settings inside a waterproof case instead.
Hydrate and snack before boarding
The trip includes water and fruit, but boarding after a light meal helps stabilize energy for an evening in the water.
Reusable water bottle
Staying hydrated before and after the swim is important in tropical evenings.
Swimwear and quick-dry layer
Wear under clothes for an easy change and comfort on the boat.
Light waterproof jacket
Evenings can be breezy or misty during the rainy season—bring a light layer for the ride back.
fall
Waterproof phone case or camera
Allows photos of the experience while protecting electronics from salt and splashes.