Semana da Marinha SOAMAR — São Francisco do Sul

The sheltered waters of Baía da Babitonga lap against the shores of São Francisco do Sul. Here, the Semana da Marinha SOAMAR — São Francisco do Sul offers an open water swimming race in the sheltered sea bay of Baía da Babitonga, on the northern coast of Santa Catarina in Brazil. Organized by Correr e Nadar, the gathering is part of the annual Navy Week festivities designed to strengthen maritime traditions and civic ties throughout the harbor community. The swimming challenge serves as a celebratory closing event of the week's nautical calendar. Swimmers can take on either a 600-meter sprint or a 1,500-meter distance. The race takes place along a safe triangular course mapped out across the placid surface of the bay. Protected from open-ocean swells by the contours of the shoreline, the bay allows participants to settle into an uninterrupted stroke rhythm from the beach start through to the finish funnel.

Ranking points and the old town on Rua Babitonga

The organiser's circuit calendar closes the year with a stage called Marinha in December, after Volta Grande in November. The Santa Catarina ranking scores 600 m, short distance (1.5 to 2 km) and long distance (2 to 23 km) as separate classifications, next to a Kids 200 m ranking and a team ranking. A stage win is worth 30 points, second place 26 and third place 24. The historic centre of São Francisco do Sul is listed by the Iphan heritage institute and holds more than 400 buildings, most of them over two centuries old. Rua Babitonga runs along the bay of the same name, with buildings renovated in their original colours. The Museu Nacional do Mar opened in 1992 in former Hoepke fishing warehouses at the corner of Rua Babitonga and Rua Manoel Lourenço de Andrade.

Baía da Babitonga: southern mangroves and estuarine wildlife

Baía da Babitonga encompasses 130 square kilometres of tidal flats, sandy beaches, and rocky shores. Its waters are predominantly salty, though salinity naturally softens during spells of heavy, persistent rain. The bay shelters 6,200 hectares of mangrove forests, representing 75 percent of all mangrove stands in Santa Catarina and standing as Brazil's southernmost continuous mangrove ecosystem. The Baía da Babitonga Wildlife Reserve is located about six kilometres from the race area. These brackish waters and mangrove root tangles form the exclusive nursery for the Uçá mangrove crab. Flocks of scarlet ibises feast on these carotene-rich crabs, acquiring their intense crimson plumage over the course of a year. Below the surface, the bay is an essential refuge for endangered marine fauna, including the Guiana dolphin, the elusive La Plata dolphin, and the massive Atlantic goliath grouper.

Forte Marechal Luz: guardians of the northern channel

Maritime navigation here dates back more than five centuries, since the French explorer Jean Binot Paulmier de Gonneville dropped anchor in Babitonga Bay in 1503. The municipality itself was established right at the northern entrance to this strategic sound on São Francisco Island. In the early 18th century, Portuguese authorities positioned an artillery battery on the headland at Ponta José Dias to protect the harbor passage. Before 1826, the outpost stood as a rudimentary wattle-and-daub redoubt fitted with four cannons. Exposed to the coastal elements, that original earthwork had fallen entirely into ruin without a trace by 1885. Military engineers revitalized the bluff starting in 1909 by erecting Forte Marechal Luz, located less than one kilometre from the swimming site. Inaugurated in December 1915, the fortress was initially fitted with heavy Armstrong artillery pieces salvaged from the cruiser Benjamin Constant before being formally deactivated in 1954.

São Francisco shoreline: fishing hamlets and Acaraí wilderness

Dozens of traditional fishing villages still line the shoreline, preserving ancestral fishing techniques that define daily life along the bay. The waterway carries the legacy of 19th-century German, Swiss, and Norwegian settlers who sailed into the interior via these passages. In 1878, the historic paddle steamer Vapor Babitonga began running passenger and cargo trips between São Francisco do Sul and Joinville, establishing the sound's first motorized connection. The bay is dotted with 14 islands, and local boat excursions routinely depart to weave among them, linking the archipelago directly with the colonial waterfront of São Francisco do Sul. Roughly ten kilometres down the island's ocean side lies Acaraí State Park, established in 2005 across 6,667 hectares of coastal plains.

The reserve shelters the wild sand dunes of the Praia Grande restinga, the pristine flow of the Acaraí River, and the Capivaru Lagoon. Its diverse ecosystems protect 337 bird species, 38 native river fishes, and 35 reptile species, including five types of marine turtles that navigate these coastal waters. Four rugged offshore islets form the Tamboretes Archipelago, a strict bird nesting sanctuary where landing is barred and waters within 50 meters are off-limits to fishing.