Pacific Open Water Challenge

The Pacific lagoon drops behind the barrier reef into clear waters teeming with sea turtles and vibrant coral formations. The Pacific Open Water Challenge is an open water swimming race held in the sheltered sea of Mulifanua, on the island of Upolu in Samoa. Organized by Samoa Events, the challenge joined the island's sports calendar in 2013 as a stand-alone event held separately from the Samoa Swim Series. Swimmers take on two long-distance ocean courses of 10 km and 5 km staged on consecutive days. Held in July, the competition takes place in warm tropical waters that eliminate the need for neoprene and let swimmers focus purely on stroke rhythm.

In past editions, when high offshore winds picked up across the open channel, organizers ran the 10 km marathon along a point-to-point route starting from Samoa Beach Resort and finishing at Manono-uta wharf. The path inside the reef creates a remarkable swim, carrying participants across living coral beds populated by diverse fish and numerous sea turtles gliding calmly beneath the surface.

Apolima Strait: volcanic rims and sunken ridges

The Apolima Strait is a 13-kilometer channel of open ocean dividing Upolu from the neighbouring island of Savai'i. This blue passage contains three small islands: Manono, Apolima, and the uninhabited islet of Nu'ulopa. Rising dramatically from the channel is Apolima, situated 2.4 kilometers northwest of Upolu's fringing reef and seven kilometers southwest of Savai'i. The island forms the rim of an extinct volcanic crater reaching 165 meters at its highest point. Shaped like an upturned bowl enclosed by sheer sea cliffs, its crater walls drop straight to the water, broken only on its northern side by a broad ocean opening that provides the main entry point into the interior. Sitting in the same strait is Nu'ulopa, a smaller, uninhabited rocky islet located between Upolu and Savai'i.

This dramatic formation rises 50 meters above sea level in the middle of the passage. Beneath the surface of the channel, Nu'ulopa rests on a submerged ridge that physically links Upolu to Savai'i across the sea floor, creating a natural underwater highway between the islands.

Nu'ulopa and the protected waters of the turtle sanctuary

The waters surrounding Nu'ulopa are recognized as a protected natural habitat for turtles. Nu'ulopa serves as an established conservation area for flying foxes. Nu'ulopa also holds deep cultural significance as the traditional burial site for the high chiefs of Manono, making the islet both a wildlife refuge and a revered ancestral sanctuary in the middle of the strait.

Submerged Lapita pottery at the Mulifanua ferry berth

The waters off western Upolu have witnessed millennia of seafaring tradition, located within an archipelago historically known to ocean voyagers as the Navigator Islands. In 1973, that ancient maritime legacy surfaced unexpectedly at Mulifanua during engineering works to expand the inter-island ferry berth. Submerged beneath the seabed, excavators uncovered an archaeological site dating back roughly 3,000 years. The submerged find at Mulifanua stands apart across the entire Pacific nation. It is the only location in all of Samoa where decorated Lapita pottery sherds have ever been unearthed.

Mulifanua waterfront: reef lagoons, ferry wharves, and village life

On the shoreline, the race hub at Mulifanua offers a relaxed island setting where swimmers gather before taking to the sea. The local resort area features two stretches of white-sand beach lined with traditional thatched sun shelters, overlooking a quiet stretch of shallow lagoon water. At high tide, this protected reef flat invites swimmers to wade in, cool off, and loosen up their shoulders. Just along the shore, the Mulifanua ferry wharf anchors the daily rhythm of the strait. As the primary terminal connecting Upolu to Savai'i, the wharf is a lively hub under the tropical sun, filled with trucks, local families, and travelers boarding boats across the water. The constant comings and goings of the ferries create a vibrant contrast to the peaceful, sheltered waters inside the reef where the swimming takes place.

The foreshore at Mulifanua is owned by local families, so asking permission before walking onto the reef or entering the water is a polite custom that keeps community ties strong. Evenings in Mulifanua wind down quietly with the sweet scent of frangipani blossoms drifting on the breeze and the low rumble of the ferry wharf in the distance. On Sunday mornings, white-clad congregations fill the village churches, sending rich a cappella hymns echoing across the road.