Princes Islands open water swimmers trace historic strait channel against autumn tides

Under an overcast morning sky, sixty-five open-water swimmers waded into the slate-colored waters off the southern pier of Heybeliada early on Sunday. Their objective was the rocky pine headland of neighboring Buyukada, separated by a deep marine channel known for sudden lateral cross-currents and crisp water temperatures. The annual community swim celebrates traditional non-wetsuit maritime swimming across the calm outer waters of the Marmara Sea.

Escorted by wooden rowboats and electric safety skiffs from the local sailing club, the swimmers faced a brisk surface current pushing outward from the Bosphorus strait. Swimmers coated their shoulders in lanolin grease to buffer the seventeen-degree water, relying on steady stroke cadences and rhythmic bilateral breathing to hold a true course against the moving water.

Navigating the deep island trench currents

The channel dividing Heybeliada and Buyukada plunges to depths exceeding seventy meters, funneling cold subsurface water that enters from the Black Sea over the Marmara shelf. Swimmers felt the temperature drop noticeably as they crossed the central channel marker, where the water turned from green-tinted coastal shallows to deep ink-navy. Maintaining a straight bearing required constant reference to the pine ridges of Dilburnu on the opposing shore.

Safety spotters aboard accompanying skiffs signaled drift angles to the swimmers with wooden paddles, ensuring no one drifted southward toward commercial shipping fairways. Swimmers formed small pods of three and four, matching their stroke rates to conserve energy against the steady current chop. Despite the absence of neoprene suits, the swimmers made consistent headway across the open channel.

“Once you enter the mid-channel trench, the water bites cold, but the pull carries you forward if you keep your stroke steady.”

Banu Ergenc, swimming club captain

Restoring island maritime community traditions

The event revives a long history of recreational sea swimming pioneered by island residents during the early twentieth century. Before modern heated pools existed, local youths spent their summers training across the archipelago's sheltered bays, building endurance for inter-island crossings. Today's event preserves that unadorned approach to open-water sport, prohibiting synthetic buoyant suits in favor of standard textile swimsuits.

Island safety teams and municipal maritime units provided comprehensive monitoring along the designated four-kilometer corridor. Organizers enforced rigorous athlete welfare measures throughout the crossing:

individual high-visibility trailing safety floats attached to every participant's waist

continuous alongside escort by historic wooden rowing skiffs from local boatyards

Landing on the pebble cove of Buyukada

The first swimmers touched the submerged pebble beach at Nizam cove just under an hour after the starting horn sounded. Wrapped in thick Turkish cotton towels and hooded woolen robes, participants gathered around a shorefront tea garden to sip hot linden tea and eat sesame simits. The conversation quickly turned to the cold water layers encountered in the channel's central trench.

Organizers confirmed that next spring's open-water season will include a youth training series focused on tidal reading and open-water safety in the archipelago. As the morning mist burned off into a calm autumn afternoon, the support boats rowed quietly back across the sound toward Heybeliada. The quiet channel waters showed little sign of the morning's rhythmic crossing.