UltraSwim 33.3 Greece [Skopelos]

Known as the Mamma Mia Edition, the multi-day route turns the open sea into a long-distance arena through sheltered bays and untamed offshore channels.

The course and formats of UltraSwim 33.3 Skopelos

Entrants can choose between two primary entry formats: the full 33.3 CLASSIC covering 33,300 metres, or the 33.3/2 BUILD option which halves the total volume to 17,000 metres. Both categories share the journey across variable maritime stages that test endurance. The course reveals the striking dual character of the island coastline. Swimmers glide through serene, sheltered bays before heading out into the choppy swells of exposed northern shores. The itinerary incorporates at least one planned island-to-island crossing, sending the pack over deep open water between isolated landmasses. Weather permitting, the program also features an optional night swim, allowing athletes to immerse themselves beneath the stars. September brings balmy conditions to this corner of Thessaly, making it the warmest stop in the entire UltraSwim 33.3 series.

Swimmers can leave behind thoughts of thick neoprene, finding comfortable late-summer sea temperatures that invite long hours of continuous stroke rhythm. Each day follows an athletic routine of early morning starts on the beach, followed by post-swim nutrition, recovery massages, and free afternoons to explore. A past edition brought together 183 swimmers from 23 different nationalities to share this island routine.

North wind, film locations and the daily swims

The UltraSwim 33.3 Skopelos course follows wild coastline that is both exposed to and sheltered from a regular strong north wind. Along the way it passes film locations of the Mamma Mia! movie, such as the clifftop island church of Agios Ioannis. The organisers name the Mamma Mia church on a rock finish line as their favourite spot of the 2024 pioneer event. The 33.3 CLASSIC spreads the English Channel distance over four days with six swims, which vary from 2 km to a marathon third day of 10 to 11 km. Sea temperatures on Skopelos in September run from 23 to 26°C (73-79 °F), the warmest water in the whole UltraSwim 33.3 calendar.

Ancient Peparethus and naval clashes at Panormus

The waters surrounding the island carry thousands of years of history dating back to the Late Bronze Age. Cretan and Minoan settlers colonized the coastline during this period, establishing ancient vineyards and introducing viticulture to the fertile hillsides. Around Staphylos and Velanio, archaeologists in 1936 uncovered a royal tomb from the Mycenaean era, confirming how deeply ingrained these shorelines were in the ancient Mediterranean world. Modern Skopelos town stands directly upon the site of the ancient city of Peparethus. About six kilometres down the coast from the primary race area lies Panormus, another ancient harbour of paramount naval importance. In 361 BCE, during the siege of Peparethus, the ruler Alexander of Pherae seized control of this natural anchorage. When the Athenian admiral Leosthenes arrived with a fleet to assist the besieged islanders, Alexander held his ground within the harbour. Using a tactical stratagem, Alexander successfully captured the Athenian triremes right inside the sheltered roadstead.

The marine park cliffs of Alonissos and Agios Georgios

The perimeter of the island is defined by dramatic cliffs that drop vertically into the open sea, leaving few natural landing beaches along its outer edges. Centuries ago, dense pine forests replaced the original oak groves because shipbuilders valued pine timber for seaworthy hulls. Today, those fragrant green pines cascade down the crags straight into the salt, giving the coastline its unmistakable emerald reflections. The National Marine Park of Alonissos-Northern Sporades was founded primarily to protect the Mediterranean monk seal, an endangered mammal that uses breeding grounds in the region. Human access to sensitive breeding areas is tightly restricted, ensuring that the wildlife can thrive undisturbed in pristine surroundings. East of the main island lies Agios Georgios, an uninhabited islet within the protected marine park.

Its perimeter consists of sheer, inaccessible cliffs that provide ideal natural shelters for nesting marine birds. Designated as a Special Protection Area, it supports breeding colonies of the European shag and Audouin's gull. Below the steep bird colonies, the islet is surrounded by a rugged, rocky seabed.

Western shores: Panormus Bay, Adrines, and Kastani

Tucked inside the sheltered embrace of Panormus Bay are the three small pebble coves of Adrines. Maritime folklore tells of a fierce pirate queen named Adrina. According to local legend, she threw herself into the bay and drowned at this very spot. Further along the western coast, Kastani beach sits beside its neighbouring shore at Milia. The bay features a sandy strip and crystalline turquoise waters, offering an ideal setting for long open-water approaches. Looking out from Kastani across the surface of the sea, swimmers take in wide-open views toward Skiathos and the uninhabited silhouette of Dasia. Lying directly opposite Milia beach, Dasia is an irregular, densely vegetated islet spanning about a third of a square kilometre. It has remained completely uninhabited since 1961, preserving a wild green profile out on the water. Just west of its irregular shores sits the rocky islet of Strongylo, completing a rugged maritime passage.