Gliding into Caló di s’Oli, Formentara, 1km from the main port town of La Savina, at sunrise, we were relieved to see an abundance of anchoring room. After bypassing our initial anchorage choice earlier that morning due to swell, it was a relief to quickly drop anchor after our overnight passage to the Islands from Cartagena, on Spain’s mainland. Deploying the anchor and checking it was set, we slumped into our berths expecting a peaceful sleep. How wrong we were.

Soon after lying down, we woke to thumping on the hull and the calls of “You are drifting!” Stumbling on deck, we confronted a fellow sailor standing in an inflatable dinghy nearby. Waving her arms, she yelled again; “You are drifting and endangering other boats. You have anchored on Posidonia. Move your boat.” The shouting continued as we apologised profusely in the vain hope of calming her. We were indeed drifting. Groggy from sleep-deprivation, we prepared to up anchor, scanning the bay for a suitable place to secure the boat.

With increasing winds we struggled to get onto a mooring, not helped by the fact that this was the first time attempting the manoeuvre in our new catamaran. With the help of kind neighbouring sailor, we finally secured Wild Heart to a mooring, breathing a sight of relief. By this time, we were frazzled and unnerved from the unexpected excitement. It was a painful initiation to the world of Posidonia in Formentera.

The Importance of Posidonia

What we didn’t understand on our arrival was the importance of Oceanic Posidonia to the health of the marine ecosystem. Now we know that this marine plant grows in meadows up to 40 meters deep and is responsible for the famous transparent turquoise waters of Formentera. In fact, Posidonia is so crucial to the environment that the fields of the Natural Park of Ses Salines d’Eivissa (Ibiza) and Formentera were declared World Heritage Sites in 1999.

Now relaxed, secured on a mooring, I slip off the yacht’s transom into the bay, surrounded by schools of tiny fish cruising through the Posidonia meadows. While the water clarity isn’t as high as anchorages we experience in the following days, the Posidonia positively sparkles in the sunshine.

The Risk to Posidonia in Formentera

With ever-increasing tourism in the Balaeric Islands, the Posidonia beds now face numerous environmental risks, including climate change, marine pollution plus anchors (and anchor chains) from visiting boats. Because of the enormous influx of yachts and day-boats visiting the famous turquoise bays during the summer, this peak period creates more pressure on the Posidonia environment. So, the marine park authority installs buoys during the busy season to protect the Posidonia beds and imposes fines for incorrect anchoring at this time. To avoid any penalties, check the location of these protected fields and book buoys via CBBASea.

Anchoring over seagrasses

Not only does anchoring cause mechanical damage of these seagrasses, they don’t always make for the most secure anchorage. Depending on the anchor types and thickness of the seagrass, the anchor may not bed securely into the seabed. So beware of anchoring over seagrass especially in the Balearic Islands, it may not be the most secure anchorage and you may fall foul of the local “Posidonia Police”. Avoid a lesson we learned the hard way.

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