Seasonal· Grande-Terre· Leeward Islands

Sargassum Season (Guadeloupe)

16° 29.2′ N · 61° 26.5′ W

Since 2011 the Great Atlantic Sargassum Belt has periodically dumped huge mats of brown seaweed on Caribbean coasts; on Guadeloupe's windward beaches and lagoons it piles up and rots, releasing hydrogen sulphide.

St Martin, Anguilla & St BarthsAntigua & BarbudaGuadeloupe, Les Saintes & Dominica

Practical

Position: Plage de la Porte d'Enfer, Anse-Bertrand (OSM way 479219282), where the national park trail notes a lot of sargassum in the lagoon. Effects (Wikipedia): decaying mats release H2S and ammonia - coughing, headaches, dizziness and nausea; about 11,000 acute sargassum-toxicity cases were reported in Guadeloupe and Martinique over eight months in the 2018 event; mats foul propellers and engine intakes and can entangle turtles. Big inundations recur every 2-3 years. For sailors: avoid anchoring downwind of rotting strands, clear raw-water strainers often, motor slowly through mats, and prefer leeward-coast anchorages (Basse-Terre west coast) when the windward coast is hit. Check local sargassum bulletins.

Best for

Knowing when to avoid the windward coast

Season

Episodic, heaviest in big Sargassum years; check bulletins

Nearby