Sargassum in Antigua and Barbuda: where to swim today, beach by beach

Live answer: today’s situation in Antigua and Barbuda is shown beach by beach on the map and in the list above, reassessed every morning from the official bulletins. Green dots (score 0-1) mark the quiet beaches, yellow or orange (2-3) a moderate presence that is still fine for a swim, red or black (4-5) the landings to avoid. On most days several beaches sit in the green even when others are loaded. Bear in mind that the picture can turn in 24 to 48 hours with the wind and the currents, and a beach that is clear this morning can take seaweed tomorrow. So rather than memorising “that beach is good”, the reliable move is to check the day’s score shortly before heading out.

Sargassum is a floating brown seaweed (genus Sargassum) that drifts in huge rafts across the sea surface. The phenomenon has escalated in recent years: pushed by the currents of the tropical Atlantic, these rafts cross the ocean from a wide belt between Africa and Brazil before reaching Caribbean shores, in Antigua as elsewhere. Out at sea they are useful, sheltering fish, turtles and crabs. The trouble is mass landings: piled on the sand, the seaweed rots within two or three days and releases strong-smelling gases. It is a natural process, but at a scale with no precedent, now closely tracked by scientific bodies and local authorities.

The rafts travel with the westbound currents of the tropical Atlantic and with the trade winds, which blow out of the east, so Antigua meets the flow with its Atlantic facade. Hog Hole Beach, a pocket of sand right by the Devil’s Bridge viewpoint, looks due east, straight into the incoming direction. Long Bay sits at the back of a bay that opens north and northeast: the sand itself faces north, but the wide mouth lets the flow in and the bay holds what enters. Further south, Half Moon Bay is a long crescent open to the southeast, exposed at an angle.

This coast has history. During the heavy season of 2018, the St. James’s Club resort on the southeast coast had to close for the whole summer, and even celebrated Half Moon Bay took a loaded episode in 2020. It is the coast to check first, not the coast to write off: exposed is not the same as closed, and on plenty of mornings the east wakes up clear.

The west coast looks onto the Caribbean Sea, in the lee of the island. To reach it, the rafts would have to round Antigua against the general drift, and most strand, break up or drift on past long before. In the north, Dickenson Bay and Runaway Beach, the two long sandy stretches near McKinnon’s, face northwest, away from the incoming flow; further down, Jolly Beach by Jolly Harbour, then Ffryes Beach and Darkwood Beach just south of it, look due west. That is what makes this shore the island’s structural fallback, the side that usually stays clear when the east is loaded.

Structural does not mean guaranteed: an unusual spell of wind can push a batch around the island, and the day’s score always has the last word.

The south is a story of angles. Around Falmouth Harbour and English Harbour, the shore is cut into deep bays that do not face the incoming east at all: Pigeon Point Beach looks northwest from inside Falmouth Harbour, and Galleon Beach faces southwest at the entrance of English Harbour. The flow has to bend around the island’s southern tip to bother them, so they are sheltered on most days without being completely out of reach: a southerly swell or an odd wind can carry seaweed into the bays now and then. The day’s score tells you whether to swim on the spot or drive the short distance to the west coast.

Barbuda, the second island of the twin-island state, is low, flat and built around a huge lagoon, and its geography is kind to swimmers. The east side takes the open Atlantic, but the great beaches look the other way: 17 Mile Beach, the immense ribbon of sand at Low Bay, runs along the barrier between the Caribbean Sea and Codrington Lagoon and faces due west; Princess Diana Beach, near Coco Point at the southern end, faces southwest, with sand that takes on pinkish tints at times from the tiny shell fragments (foraminifera) mixed into it. Both sit in the lee of the island, downstream of the flow.

A loaded morning is rare on that side, but nothing at sea is ever fixed: check the score before committing the day.

The season mainly runs from March to October, often peaking between April and August, but it varies a lot from one year to the next. Some years bring almost nothing, others break records. A landing lasts from a few days to several weeks, with no guaranteed end date: everything depends on the rafts drifting in from the tropical Atlantic, on the currents and on the wind direction. In practice there are calm windows in the middle of the season, and an arrival remains possible outside it. That is why a daily update, beach by beach, is worth far more than a seasonal average when you are deciding where to swim.

In the great majority of cases, no: a beach with light or moderate sargassum poses no risk for swimming in Antigua. The risk comes with heavy, prolonged landings. As it decomposes, the seaweed releases hydrogen sulphide (H₂S) and ammonia, which smell of rotten eggs. In high concentrations these gases can bother sensitive people, such as asthmatics, babies and pregnant women, and they tarnish jewellery and electronics. Authorities close the worst affected spots (black score). For a visitor the rule is simple: as long as the smell stays faint and the score is below red, the beach is fine to use. That is exactly what the odour index shown on each beach summarises.

Partly, yes. The forecast rests first on satellite monitoring of the offshore rafts: imagery picks them up tens of kilometres out, which opens a window of a few days depending on the currents and the trade winds around Antigua. Over a longer horizon, monthly bulletins (NOAA, University of South Florida) estimate how much seaweed is sitting in the Atlantic, and therefore the risk over the coming weeks. FanGass combines those satellite outlooks with the official weather bulletins to anticipate, beach by beach, where a landing is likely. Since no forecast is fully reliable, as a change of wind can rewrite everything overnight, the daily update is what really makes the difference.

Antigua and Barbuda treats the seaweed as a national matter. The Department of Environment publishes a seasonal sargassum outlook online, public crews are sent to clean the busiest beaches, and the hotels rake their own beachfront. More recently, the Coast Guard took delivery of a purpose-built aquatic harvester, supplied through Japanese cooperation, to intercept the rafts at sea before they strand. None of that makes a heavy season disappear, but it shortens the bad days on the most visited beaches, and it is one more reason why a beach marked red one morning can be back in the orange a few days later.

Every monitored beach in Antigua and Barbuda gets a score from 0 to 5 and a colour. Green (0-1): quiet, go ahead. Yellow (2): a little sargassum, swimming is fine. Orange (3): a moderate, visible amount, but you can still swim; plenty of people do, and you decide based on the smell that day. Red (4): heavy landing, strong smell, better to avoid. Black (5): evacuated zone. The rule worth remembering: only red and black are genuinely to be avoided, and below that swimming remains possible. An odour index (none / faint / strong) completes the score, because it is often the smell of decomposition, more than the seaweed itself, that ruins the outing.

There is no need to cancel a holiday in Antigua: with a whole leeward coast to choose from, there is almost always a swimmable beach, and most stay swimmable even with light to moderate sargassum. If you are worried, book your beach days on the west coast (Dickenson Bay, Jolly Beach, Ffryes, Darkwood), keep Pigeon Point and Galleon Beach in mind in the south, and remember that Barbuda’s 17 Mile Beach and Princess Diana Beach face away from the flow. But do not write off the east outright: on plenty of days Long Bay and Half Moon Bay are perfectly pleasant, and they are among the island’s most beautiful spots. The best move stays the same: check the day’s score, beach by beach.

Every morning, FanGass gathers the official monitoring bulletins (the Department of Environment and its seasonal sargassum outlook, NOAA AOML, the University of South Florida monthly outlook and the local press, Antigua Observer in the lead), cross-checks them against satellite imagery of the offshore rafts, and boils it down to a score from 0 to 5 per beach in Antigua and Barbuda. User reports from the ground adjust the scores live when several agree, and everything is reassessed each day. The service is free, edited by the Katchak agency.