UltraSwim 33.3 Greece

The UltraSwim 33.3 event in Milos covers a full 33.3-kilometer distance, challenging participants to circumnavigate the volcanic coastline of this Aegean island. Swimmers must contend with the prevailing north winds that dictate the conditions on exposed stretches, while finding respite in the island’s naturally sheltered bays. Logistically, the race requires support craft to manage the transit across varied coastal terrain, including the passage near the clifftop church of Agios Ioannis. The water here is defined by the geography of a massive submerged crater, where the depth drops rapidly from the shoreline.

Navigating volcanic waters

As you progress along the western coast, the route passes the collapsed roof of the Sykia sea cave, a clear indicator of the intense volcanic erosion that shaped these cliffs. Further along, the eastern shore presents a more visceral geological experience: active hot sulfurous springs that release minerals directly into the sea, a phenomenon documented since the time of Pliny the Elder. This volcanic activity is matched by a complex human history visible from the water, such as the remains of the Phylakopi Bronze Age settlement, where parts of the ancient town wall now lie submerged beneath the surface.

Naval history remains a constant companion on this course. The area around Milos has served as a strategic maritime theater for centuries, including the site of the 1661 naval engagement between the Republic of Venice and the Knights Hospitaller. Later conflicts also left their mark; the wreck of the SS Artemis Pitta, sunk by aircraft during World War II, rests in these waters as a reminder of the island's mid-century volatility. Swimmers will also pass the white volcanic cavities of Kleftiko, once the primary base for pirates who utilized the complex cave systems to ambush merchant vessels during storm-driven maritime traffic. Those seeking additional challenges in the region can look to the 2026 edition of the Milos circuit, which provides a different pacing for those managing these Aegean currents.