North Shore Swim Series — Chun's Reef to Waimea

The North Shore Swim Series — Chun's Reef to Waimea is an open water sea race held in Waimea Bay, near Haleiwa on the island of Oahu in Hawaii. Organized by the Waikīkī Swim Club, the event is scheduled during the summer month of July. The race forms part of the North Shore Swim Series, a five-race circuit that began in the 1980s and has been held for 27 consecutive years on the North Shore of Oahu. Across the broader series, open water courses include distances of 2,000, 5,000, and 10,000 meters. The competition from Chun's Reef to Waimea Bay covers a 1.6-mile course along the coast. Swimmers enter the sea at Chun’s Reef, near the surf spot known as Piddlies, and follow the coastline east toward Waimea Bay.

The race begins with a mass start in the water, where swimmers line up behind two 40-inch buoys before setting out across the open sea. The course is marked by 40-inch guide buoys that swimmers can navigate inside or outside of, unless surf conditions require staying on the outside line. Participants make their way through warm, clear water over living reefs and past world-famous surf breaks along a lush, green coastline. The transparent conditions allow swimmers to track the underwater landscape beneath them while keeping sight of the verdant shore. The finish line is located directly in front of the lifeguard tower at Waimea Bay. To complete the swim, racers sight an eight-foot triangle buoy that they must keep on their right shoulder before running up the sand.

North Shore swells: from winter monsters to summer glass

The North Shore of Oʻahu spans between Kaʻena Point and Kahuku, a coastal area famous for winter swells originating in the North Pacific. During the peak winter season, those swells create massive waves reaching heights of 45 to 60 feet. On November 7, 1957, riders achieved the first successful attempt to ride the giant waves at Waimea Bay. The winter conditions are renowned for their raw power, and the Quiksilver Big Wave Invitational at Waimea Bay requires consistent 20-foot waves to be held. Yet while winter surf reaches extreme heights, the water in Waimea Bay is typically clear and calm during the summer months when the race takes place.

The North Shore also features protected coves suitable for beginner surfing lessons. At the Banzai Pipeline, three distinct reefs lie at progressively deeper depths that activate based on the size of ocean swells. Sand accumulating on the reef can cause waves to break unpredictably and violently, while a strong west swell clears the sand and a strong north swell creates the best wave conditions. Further along the North Shore, Sunset Beach forms a 3.3-kilometer stretch of sand. Waves at Sunset Beach are generated by west-to-northeast swells originating from the North Pacific, and extreme surf in 2013 and 2014 swept private property, including swimming pools and staircases, into the sea. In December 2017, large waves caused severe sand erosion that carved a 20-foot cliff along the bicycle trail.

Sacred headlands of Waimea Bay: Kaneaukai and Pu'u o Mahuka

At the water's edge of Waimea Bay stands Ke Ahu Hapu'u, a sacred temple. The shark god Kaneaukai is honored at this Ke Ahu Hapu'u fishing shrine. On the heights above the bay, visitors can explore the remains of the Pu'u o Mahuka temple. About two kilometres from the race area, in the Waimea Valley, ancient Hawaiians constructed complex fish ponds.

Waimea River: red waters, sandbars, and valley pools

The Waimea River is formed by the confluence of the Kamananui and Kaiwikoʻele streams. The total length of the river, including its tributaries, reaches 24.4 kilometers. In the Hawaiian language, the name Waimea translates to "reddish water" or "red water". Ancient Hawaiians practiced a water activity called Wai Pu'uone, riding waves into the river mouth when blocked by sand bars. Today, the river mouth is known for waves generated when the beach is dredged to create a drainage channel. Cliff diving exhibitions are held at the waterfall in Waimea Valley.

The Waimea Bay seafront: golden sand, Da Rock, and food trucks

Waimea Bay is a crescent-shaped natural bay with a wide, sandy beach. The beach park features a large grassy area outfitted with picnic tables and shaded trees. After finishing the swim and emerging from the surf, competitors can gather on the grass beneath the trees to recover from the morning effort. The open sweep of sand provides a peaceful vantage point to take in the calm summer ocean. On the left side of the bay, a large rock formation known as "Da Rock" serves as a popular spot for cliff jumping. Local families often fish from the shore of the bay during the summer months. Food trucks are available near the bay, offering local dishes like garlic shrimp and shave ice. The beach is also a popular location for watching sunsets over the water, especially after the crowds have left.