Circuito TH5 Travessia — Etapa 5 (Bertioga)

Swimmers take to the open waters of Praia da Enseada right beneath Forte de São João. The Circuito TH5 Travessia — Etapa 5 is an open water swimming race held in the Atlantic ocean at Bertioga, on the coastal shoreline of the state of São Paulo in Brazil. Setting off from the firm sand in the town center, swimmers wade straight into the sea surf before finding their rhythm across the bay. Open ocean swells give the starting stretch an unmistakable rhythm, framing a dramatic course right off the historic waterfront. The competition offers a progression of courses tailored to both newcomers and seasoned distance swimmers, featuring offshore sea courses of 700 metres, 1,200 metres, and 2,200 metres.

Young athletes also take part on the same shoreline in a dedicated Kids Swim over a 150-metre dash for swimmers between the ages of 5 and 12. Swimmers navigate out into the bay guided by marker buoys, tracking back toward the beach against the open horizon. This gathering represents the fifth stage of the annual circuit, dedicated under the name Perseus. It carries forward a long-standing coastal tradition curated by TH5 Eventos, an organization that first began hosting seaside athletic competitions back in July 1993 in the neighboring city of Santos. The waters surrounding the fort serve as a vibrant hub for ocean disciplines; during the circuit's multi-sport program, outrigger canoes launch directly beside Forte São João, steering into the Bertioga Channel and heading up into the mouth of the Itapanhaú River to round a turn buoy set four kilometres upstream.

Etapa 5 conditions: 21°C (70 °F) water and wetsuits permitted

On 27 September 2026, the day of Etapa 5 of the Circuito TH5, the results page recorded air at 22°C (72 °F), water at 21°C (70 °F) and wetsuits permitted. At Etapa 4 on 2 August 2026 the recorded conditions were 25°C (77 °F) air, 21°C (70 °F) water and wetsuits permitted. The 2026 circuit lists five stages, on 1 February, 22 March, 31 May, 2 August and 27 September. The aquathlon comes in a long version, a 750 m swim followed by a 4 km run, and a short one, 400 m of swimming and a 2 km run, both from age 10. In the Travessia the final time is taken once the swimmer has left the water and passed the finishing gantry. Praia da Enseada is a 12 km beach with calm water and views of the mountains.

Forte de São João: the stone bastion guarding Bertioga

Rising right above the sand where the starting gates assemble, Forte de São João da Bertioga guards the natural bar of the Bertioga Channel directly opposite the island of Santo Amaro. The defensive compound was designed to control maritime access into the Rio Bertioga canal. The military presence on this narrow coastal threshold dates back to the earliest years of European arrival. In 1551, an initial palisaded settlement raised on this spit by Diogo de Braga and his sons was completely overwhelmed and burned in an assault mounted by the indigenous Tupinambá people. The strategic value of the channel mouth remained vital, and in 1563 the Jesuit priests Manuel da Nóbrega and José de Anchieta halted at the fortified outpost to celebrate mass together before setting sail toward Iperoig.

The fortress visible from the race staging area today owes its robust architecture to an extensive reconstruction completed in 1710, when engineers rebuilt the stronghold with thick stone and lime masonry and equipped its batteries with eleven heavy artillery pieces. Throughout the eighteenth century, the fort operated as a mandatory inspection and registration post for merchant vessels and seafaring traffic navigating the coastal waterways toward the bustling port of Santos.

Praia do Perequê: river wildlife and fishing colony

Across the channel waters along the adjoining coast lies Praia do Perequê, an expansive beach stretching for 2,400 metres along the edge of Santo Amaro island. At one section of the beach, a freshwater river discharges directly into the Atlantic, creating an estuarine nursery that ebbs and flows with the tides. Schools of fish and marine crabs ride the rising tide upstream into the brackish currents, before flushing back out to sea as the water recedes on the outgoing ebb. The protected riverbanks provide a thriving sanctuary for local wildlife, where semi-aquatic capybaras graze alongside otters and an array of feeding coastal birds patrolling the shallows. Perequê maintains deep maritime roots as the largest active artisanal fishing colony in the municipality of Guarujá. Tucked away on the left flank of the inlet, a small freshwater waterfall cascades down from the coastal greenery straight toward the shoreline. Natural running water provides an authentic coastal backdrop to explore just beyond the race area.

Morro do Mar Casado: the tidal tombolo of Pernambuco

Continuing down the island coastline, Praia de Pernambuco unfurls across 1,800 metres of sand. At Morro do Mar Casado, a dramatic headland, a striking natural phenomenon takes place with the daily change of tides. When the tide rises, the waters of Pernambuco and the adjacent Mar Casado beach advance and merge across the sandspit, effectively cutting off the rocky promontory and converting the hill into a temporary island. The natural isthmus connecting the mainland to the hill is a geological tombolo, a rare coastal formation along the shores of São Paulo state. The steep flanks of the headland rise at sharp inclinations predominantly exceeding 45 percent, leaving its slopes naturally vulnerable to coastal erosion and sliding. To safeguard this delicate ecological balance and its unique geological profile, the island is permanently protected as an official natural heritage site.