Cold Half

Winter along the rugged southern shores of Hong Kong Island strips away the tropical haze, offering open-water swimmers a crisp 15-kilometre traverse from the outer peninsula of Stanley to the sheltered curve of Repulse Bay. Known as the Cold Half, this winter marathon swim navigates the open sea along one of the territory's most dramatic coastlines, organized jointly by AVRA and 26 Coaching. Swimmers take to the salty swell in the cooler winter climate of January, trading warm summer humidity for brisk, clear conditions. Setting off from Stanley Main Beach, the marathon distance covers 15 kilometres of open water across the southern edge of Hong Kong Island. In past editions, swimmers have followed a coastal hug route departing from the beach, rounding the satellite headland into Stanley Pier, skirting the dramatic promontories of Chung Hom Kok and South Bay, cutting across the bay, and navigating past Middle Island.

Staying on schedule is essential: the 15-kilometre course enforces a strict cut-off time of five hours at Round Island and six hours overall to reach the finish arch at Repulse Bay Beach. Winter conditions along this stretch of coast bring sea temperatures hovering around 18 to 20 degrees Celsius, often paired with air temperatures in a similar range. While some days begin with choppy seas and lively coastal winds, the breeze frequently moderates as swimmers turn into the sheltered western bays. For those swimming without a wetsuit, the sustained exposure demands steady pacing and deep cold tolerance. Participants under 16 years of age are required to wear a wetsuit whenever the water drops below 20 degrees Celsius, ensuring younger athletes remain safe in the brisk maritime climate.

Solo 15-kilometre swimmers must be accompanied by an escort motorboat or a dedicated support paddler in a kayak, while relay teams must operate alongside a designated motorboat. The minimum age to tackle the full distance solo is 16, while relay teams accept swimmers from 14 years old. In addition to the marathon, the event stages shorter alternatives, including the 1.5-kilometre Cold Plunge and the 400-metre Cold Sprint, alongside an ice bath challenge where brave finishers plunge into water chilled to 3 degrees Celsius.

Stanley Bay and Peninsula: typhoon shelters and maritime heritage

Before launching into the open sea, swimmers gather on the eastern side of the Stanley peninsula, a landform steeped in southern maritime heritage. Historically, the sheltered anchorages of Stanley Bay and neighboring Tai Tam Bay provided vital havens for the indigenous Tanka boat-dwelling community, whose fleets sought sanctuary here during catastrophic typhoons.

Chung Hom Kok and Round Island: pirate caves and wartime batteries

Rounding the first major headland of the marathon course brings swimmers alongside the peninsula of Chung Hom Kok, framing a tucked-away sandy pocket measuring 169 metres in length. The western cove boasts Grade 1 water quality, offering exceptional clarity beneath the surface as swimmers trace the outer contour of the point. It is an atmospheric stretch of coastline where sheer rock faces meet the ocean swell. Hidden at the foot of these sea cliffs lies Cheung Po Tsai Cave. Local legend maintains that this narrow coastal cavern served as a secluded hideout for the Qing dynasty pirate Cheung Po Tsai. Looking directly across the water from Chung Hom Kok, the low hump of Round Island marks the race's decisive checkpoint. Striking across this open stretch requires disciplined sightlines and trust in your support paddler, as swimmers must clear Round Island within five hours to remain on course for the finish.

From South Bay to Repulse Bay: coves and seaside retreats

Once past the outer points, the marathon course funnels swimmers into the serene indentations of Hong Kong Island's southern shoreline. South Bay welcomes tired arms with calm waters, backed by a 250-metre strip of soft sand and gentle green hills. Equipped with beach showers, changing facilities, and barbecue pits, this peaceful cove provides a quiet counterpoint to the busy headlands behind you. Continuing northward, the route glides past Middle Bay and cuts inside Middle Island, which buffers the coastal channel between Repulse Bay and Deep Water Bay. Gliding into the final bay, the open ocean gives way to protected, welcoming water. Repulse Bay Beach itself forms a wide, 292-metre crescent of sand that ranks among the longest public beaches in Hong Kong.

First developed into a premier seaside bathing resort in the 1910s, Repulse Bay was later artificially extended to welcome generations of beachgoers. Its western headland was once famously crowned by Eucliffe, a flamboyant stone mansion with an outdoor swimming pool that overlooked the bay from the cliffside. Today, the sweep of sand maintains an official Grade 1 water quality rating, offering swimmers a clean, luminous finish after their long coastal journey.

Stanley Main Beach seafront: water sports and coastal culture

Back at the starting line, Stanley Main Beach remains one of Hong Kong's most energetic coastal playgrounds. Stretching for 194 metres along the eastern shoreline of the Stanley peninsula, the beach sits only a short stroll from the vibrant alleys of Stanley Market. The bay is fitted with shark-prevention netting, giving swimmers peace of mind when training along the shore before heading out into the open marathon course. The beach serves as a focal point for windsurfing and local water sports. These same starting waters host the boisterous spectacle of the annual Dragon Boat Championships, filling the bay with pounding drums and churning oars. Public barbecue pits line the sand, providing an ideal spot to fire up a post-race meal and share stories of navigating the southern headlands. Surrounded by Grade 1 sea water, it is a magnificent stretch of coastline to start a winter swimming adventure.