16. Biserov plavalni maraton in DP 5km OWS 2026

In 1958, the coastal town of Portorož transformed into a global stage for the major international chess tournament, a contest that saw a young Bobby Fischer clinch his grandmaster title at the record age of fifteen. Today, the same bay that hosted this intellectual intensity serves as a far more physical arena for open water swimmers. The Biserov plavalni maraton, now in its 16th edition, invites participants to navigate these historic waters, connecting the legacy of a quiet strategic retreat to the endurance required for a 5km competition.

Navigating the bay

As you begin your stroke, the coastline reveals markers of a complex maritime past. The area takes its name from the 13th-century church of Santa Maria delle Rose, a structure that vanished long ago but left its etymological mark as 'Portorož'. Swimmers often pass near the Fizine coast, where, in the 1920s, a bustling hydroplane base and pilot school operated, linking the town to Venice and Turin through the air. The view is dominated by the ridge of Beli Križ, where the Radio Capodistria antenna serves as a high-ground landmark.

Water and history

The bay is characterized by a humid subtropical climate, resulting in waters that remain warm through the late summer season. Beneath the surface, the history is just as tangible; swimmers can occasionally spot the submerged remains of a Roman port and an ancient fish farm near the Monfort salt warehouses. The route also offers a clear perspective of the bell tower of the Bernardin monastery, a 15th-century religious site later converted into a military fortress by the Austrian army in 1830 to guard the bay. Whether you are aiming for the podium in the 5km national championship or testing your pacing, this course balances the heritage of Venetian fleet refuges with the demands of modern racing. For those seeking additional local challenges, the season offers variety, such as the Sunrise Swim Portoroz in June or the Mini Maraton Koper in September. The Benedictine monks once treated ailments with the very salt water you traverse, a reminder that this bay has been a destination for healing and movement for centuries.