Posidonia meadows run along much of the Formentera coast, close enough to the beach to reach with a mask and fins. What to look for, when the water is clearest, and how to look without leaving a mark.
Summerbest time
La Savinanearest area to stay
1.4 kmfrom La Savina port, straight line
The seagrass meadows off Formentera are the reason the water is so clear: the leaves slow the swell, settle the sand and hold the seabed in place. You can see them from the surface, without a boat, at several beaches within a short ride of La Savina. This page covers where to get in, when to go, and the rules that keep the meadows intact.
01
What the meadows are
Posidonia oceanica is a flowering seagrass, not seaweed. It lives only in the Mediterranean, and off Formentera it forms meadows that cover the seabed from the shallows out to about 30 or 40 metres. The leaves are long green ribbons that turn brown as they age and break away. Underwater the meadow looks like grassland in slow motion, and the matted roots and rhizomes hold the sand in place and keep it from washing away.
You do not need to dive to see it. From the surface, in calm clear water, the meadow shows as dark patches between pale sand, and the ribbons lean with the current. Between Ibiza and Formentera the meadows and coastal ecosystems form part of the UNESCO World Heritage Site 'Ibiza, Biodiversity and Culture', listed in 1999. The sea here lies inside the Ses Salines Natural Park, declared in 2001, a Ramsar-listed wetland where salt is still harvested.
The meadow is not scenery. It is the reason the sand stays white and the water stays clear.
02
Where to get in
Most people start at La Savina, the port at the western end, and walk or cycle north towards Ses Illetes. The water is shallow for a long way, the bottom is a mix of sand and seagrass, and you can wade in and put your mask on without a boat. Take the quieter beach access points rather than the busiest strip and the meadow edge is a short swim away, in water clear enough to see your own fins.
The rest of the island offers different ground. At Es Caló de Sant Agustí the old boat houses sit over rock and weed; at Cala Saona the bay is enclosed and often calm; along Platja de Migjorn the seagrass comes and goes with the season as the sand shifts. Everywhere, the interesting line is the boundary between pale sand and dark meadow, where fish move and the light changes.
La SavinaShort walk from the port, shallow entry, meadow edge close to the beach.
Ses IlletesSand and seagrass in clear water inside the natural park; go early.
Es CalóRock and weed beside the boat houses, good in calm weather.
Cala SaonaEnclosed bay, sheltered entry, easy for a first attempt.
A fish over rocks and seaweed under the water off Formentera03
The best time to look
Summer is the season, from June to September. Typical sea temperatures are about 22-23 °C in June, 25-26 °C in August and 23-25 °C in September, which means you can stay in the water long enough to look properly. Mornings are usually calmer, and the light is best when the sun is high, roughly from late morning to mid afternoon, reaching into the meadow instead of reflecting off the surface.
Wind decides more than the calendar. A day of strong wind stirs the shallows, lifts the sand and drops visibility, and the water needs a day to clear again. After a blow, torn posidonia leaves collect on the beach, which is natural and part of how the beach is built. Some bays stay sheltered in most conditions and others are exposed, so ask locally which way the wind is going before choosing a spot.
04
How to do it
A mask that fits, a snorkel and a pair of fins are enough. Fins are not for speed: they let you lie flat and hover without putting hands or knees on the bottom. Put the mask on in shallow water, breathe slowly, and swim out over the sand until the dark patches begin. Keep your body horizontal and your fins high, well above the leaves, and stop kicking when you want to look down.
Then stop moving. A meadow rewards stillness: fish move between the leaves, small animals live on the blades, and the green changes as the light shifts. Look for the older brown leaves, the pale sand channels and the darker hollows where the mat is thickest. Do not chase anything, do not put a hand down to steady yourself, and keep a metre between your fins and the bottom.
05
The rules on the water
Anchoring over the meadows is regulated by a Balearic decree, and mooring buoys are installed in some bays in summer. On a boat, use a buoy where one exists, or anchor over sand in water deep enough that the chain does not drag across the leaves. Anchors and chains cut scars that take a very long time to close. The rules are enforced, and the details change, so check before you set out.
Inside the Ses Salines Natural Park, which covers the north of Formentera and the sea between the two islands, the rules are stricter again. Speed, anchoring, mooring and access can all be limited, and the natural park office knows the current position. The Consell de Formentera publishes the island's own rules, including the summer limits on visitor vehicles. Read both before you arrive with a boat or a car.
Sailing boats over clear water and dark seagrass near Formentera, from the air
Check before you goAnchoring rules, buoy fields and the summer vehicle limits change. Confirm the current position with the Consell de Formentera and the natural park office before you sail or drive.
06
Doing it lightly
Posidonia grows slowly. A meadow scarred by an anchor can take decades to recover, and the leaves that wash up on the beach are not waste: they hold the sand, feed the beach and shelter small animals. The clear water that makes the snorkelling good is produced by the meadow itself, which settles what moves through it. Treat the meadow as the reason you came, not as something to get past.
In practice that means a few habits. Do not stand on the leaves, do not drag equipment across them, and take nothing: no shells, stones, plants or animals. Keep the group small and the movement quiet. Choose sun protection that stays on your skin and shower afterwards rather than letting it wash into the water, and carry any rubbish back to the bins at La Savina or Es Pujols, where it can be dealt with properly.
Do not standFins up and body flat, with nothing resting on the leaves.
Do not anchorUse a buoy where there is one, or anchor over sand.
Take nothingNo shells, stones, plants or animals, alive or otherwise.
Stay quietSmall groups, slow movement, sun protection that stays on.
Protect itThe meadow is what keeps the water clear. Look at it, hover above it, and leave it exactly as you found it.
07
What to bring
Bring your own mask if you can, because fit matters more than any other piece of equipment and a leaking mask ends a swim early. Fins, a rash vest for sun and warmth, a towel and drinking water cover the rest, and a dry bag keeps a phone and a key safe. Equipment hire and boat trips run roughly from May to October; much of the seasonal business closes from November to April.
There is no need for a boat. The meadows begin close to the shore at La Savina, Ses Illetes and Es Caló, and the best sessions are short: twenty minutes in the water, a rest on the sand, then another look. With children, keep everyone within arm's reach and stay in the shallow part of the meadow, where the light is best and the bottom is easy to read.
Mask firstA good fit matters more than any other item you carry.
FinsThey let you hover flat instead of steadying yourself by hand.
Rash vestSun and warmth for long sessions in the water.
Dry bagFor a phone, a key and anything that must stay dry.
08
Nearby and after
La Savina is the natural base. The ferry from Ibiza Town takes about 30-35 minutes on the fast service and about an hour on the conventional one, and the port puts you within a short ride of the northern beaches. The signposted green routes link beaches, lagoons and villages by bike and on foot. The Estany des Peix and Estany Pudent lagoons are minutes away and worth an evening walk.
Further east, Es Caló and its boat houses make another good base for a morning in the water, and Es Pujols has the megalithic tomb of Ca na Costa nearby. La Mola and its lighthouse stand above the eastern end, Cap de Barbaria at the southern one. Out of season the island empties, the water cools, and the meadows are still there, which is the point of the whole page.
Formentera has no airport, so the route is always a flight to Ibiza and then the ferry from Ibiza Town to La Savina. Sailings are frequent in season and fewer in winter, and the operators publish their own timetables. The tourist tax is charged by the accommodation and the rate depends on its category and the season, so check the Govern de les Illes Balears pages rather than relying on a figure quoted last year.
Where to wake up
Stays near posidonia
Stays near posidonia: the first 6 of 24 stays in the IMPT hotel database in or close to La Savina, the nearest area to Snorkel over posidonia, five-star first, then four-star, then by guest score. Each button opens live prices for your dates in the IMPT app.
Where can you snorkel over posidonia on Formentera?
Several beaches put you over the meadow within a short swim. The northern coast around La Savina and Ses Illetes is the easiest, with shallow water and a clear edge between sand and seagrass. Es Caló de Sant Agustí works over rock and weed, Cala Saona in calm weather, and stretches of Platja de Migjorn when the sand has settled.
Do you need a boat to snorkel over posidonia in Formentera?
No. The meadows begin close to the shore in several places, and at La Savina and Ses Illetes you can wade in and swim a short distance to reach them. A boat helps if you want the densest parts or a trip towards Espalmador, but the shallow edge is where the light is best and most of the life is.
When is the best time to snorkel over posidonia in Formentera?
From June to September, when the sea is warmest and you can stay in comfortably. Typical temperatures are about 22-23 °C in June, 25-26 °C in August and 23-25 °C in September. Calm mornings with high sun give the clearest view into the meadow; after a windy day, wait for the sand to settle before trying again.
Can you snorkel over posidonia without fins?
Yes, in shallow water. Fins help you lie flat and hover without touching the bottom, which protects the leaves and makes the swim easier, but at La Savina and Ses Illetes the meadow edge is close enough to reach without them. Without fins, keep your legs still and move your arms slowly rather than kicking down.
Is anchoring over posidonia in Formentera allowed?
Anchoring over the meadows is regulated by a Balearic decree, and in some bays mooring buoys are installed in summer. Where a buoy exists, use it; otherwise anchor over sand, in water deep enough that the chain cannot drag across the leaves. The natural park office and the Consell de Formentera can confirm the current rules before you set out.
What can you see while snorkelling over posidonia in Formentera?
The meadow itself is the sight: long green ribbons that turn brown with age, pale sand channels between patches, and small animals living on the blades. Fish move through the leaves, and the light changes the colour of the meadow as the sun shifts. Look for the darker hollows where the mat is thickest, and keep still to let the life return.
Is snorkelling over posidonia suitable for children?
Yes, in the shallow water close to the beach, with an adult within arm's reach. A well-fitting mask is the main thing, and a rash vest helps with sun and warmth. Stay where the bottom is easy to read and the meadow edge is close. Children usually take to it quickly because there is something to see within a few metres of the sand.
How do you snorkel over posidonia without damaging it?
Lie flat, keep your fins high and never stand or kneel on the leaves. Do not anchor over the meadow or drag equipment across it, and take nothing away. Stay a metre above the bottom, keep the group small, and use sun protection that stays on your skin rather than washing into the water. Speed is the enemy: hover, look, and move on.
Is the posidonia off Formentera in a protected area?
Much of it is. The meadows between Ibiza and Formentera form part of the UNESCO World Heritage Site 'Ibiza, Biodiversity and Culture', listed in 1999, and the sea and the northern shore lie inside the Ses Salines Natural Park, declared in 2001. Posidonia itself is protected, and the anchoring rules that apply over it are enforced.
