International Datça Open Water Winter Swimming Marathon

The Datça Open Water Winter Swimming Marathon is an open water swimming race held in the sea at Datça, Turkey. First organized in 2007 by the Datça Municipality, it holds the distinction of being the first regularly organized international winter open water swimming marathon in the country. Held in January, the marathon draws distance swimmers into the sea for two distinct challenges: a 1,500-meter sprint and a 5,000-meter test. The single-lap routes trace a carefully marked bay, lined with guide buoys positioned every 500 meters and four turning buoys to steer competitors across open water. Sighting across the swell, swimmers navigate long lines of floating markers before rounding the outer turns back toward the shore. What truly sets this winter gathering apart is the remarkable character of the bay. Taşlık Beach rests in a naturally sheltered inlet that stays warmer through the cold months than other Aegean coastal waters. Winter water temperatures have remained close to nineteen degrees, turning a midwinter marathon into a surprisingly gentle swim.

The Datça Peninsula between Gökova and Hisarönü

The race unfolds along the narrow spine of the Datça Peninsula, an eighty-kilometer finger of land cleaving the Aegean Sea. Stretching from east to west, this slender landmass divides the sweeping Gulf of Gökova to the north from the deep pocket of the Hisarönü Gulf to the south. Swimmers look out upon a coastline carved by nature into countless secluded bays and jagged inlets. To the north, the Gulf of Gökova opens into a vast maritime corridor running one hundred kilometers between the Bodrum and Datça headlands, framed at its outer mouth by the Greek island of Kos. While the north coast of the peninsula faces low terrain and expansive beaches swept by summer meltem winds, the southern shoreline where the race gathers is defined by rocky, deeply indented cliffs.

Ancient Knidos and the submerged wrecks of Yassi Ada

Maritime history runs through every stretch of water off the peninsula. At the far western tip at Tekir lies the classical city of Knidos, situated beside Cape Deveboynu, which remains tied to the mainland by a narrow spit of land once used as a causeway in antiquity. Farther east, at the narrow Balıkaşıran isthmus where sailors dragged small boats between the two gulfs, the people of Knidos attempted in 540 BC to carve a canal through the rock to turn their home into an island, abandoning the work only after consulting an ancient oracle. The open sea also carried ancient dangers that shaped the shoreline. Fear of pirate raids forced historic coastal settlements to retreat more than a mile inland, leaving the immediate water edge wild and unsettled. Byzantine maritime law went so far as to forbid all sailing between November and March due to the risks of pirates and harsh winter weather.

İskele harbor and the seafront of Taşlık Beach

The marathon centers on the bustling İskele neighborhood, the harbor heart of Datça. Taşlık Beach sits directly within the district. It is a shore where town life and open water meet effortlessly, making the transition from a long sea swim to a warm post-race meal seamless. Maritime heritage remains alive along the harbor, where traditional seamanship customs and festive gatherings mark events like the annual Cabotage Festival.

Taşlık Beach in January: thermal pond and sea temperature

Taşlık Beach lies beside a pond of thermal spring water that flows into the sea, which keeps the winter seawater warmer than in other regions. The surrounding hills protect the beach from strong winds, which gives the swim a calm, pool-like setting. Datça Meteorology Directorate figures listed by the organisers put the sea at Taşlık Beach at 18.9 °C (66 °F) in 2024, 18.7 °C (66 °F) in 2023 and 18.5 °C (3673-65 °F) in 2022. The time limit is 60 minutes for the 1500m course and 150 minutes for the 5000m course, and swimmers who cannot finish in time are taken out of the water by boats. Judges follow the swimmers in boats and intervene only to warn them about problems with the designated course.