In Brazil, the local word for anaconda is Sucuri — and they can grow up to 25 feet in length. In the mighty Amazon, the vast spiderweb of writhing rivers and impenetrable bogs live vicious piranhas, prehistoric reptiles, mysterious shapeshifters and other fearsome creatures.

Brandon Cole

"The snake is almost four times as long as I am tall. Its slick chestnut scales glisten with an iridescent sheen, shifting from metallic blue to green to yellow. Beautiful. A forked tongue flicks like a bolt of purple lightning. Sinister."

Brandon Cole

"My wife, Melissa, ever the brave, curious sort, beats me into position and glides in close to the sucuri (the native word for anaconda) for a proper inspection — fascination obviously trumping fear."

Brandon Cole

With a boxy, lumpy profile in stark contrast to their cousins’ stereotypical svelte form, and small, beady eyes that appear almost an evolutionary afterthought, the Amazon river dolphin won’t steal hearts with dashing good looks.

Brandon Cole

Whereas the anaconda was aloof, the botos are downright gregarious, and local legend claims river dolphins take human form at night to seduce women.

Brandon Cole

The boto’s pink is a result of their thin skin that allows the color of blood to be seen through the dermis.

Brandon Cole

Rapids in the Rio Olho d’ Agua force a short portage to reach what our guide calls the “sand volcano.” Like an underwater Krakatoa, the jet of warm water gushing from the Earth’s core boils and churns the sand in an endless eruption.

Brandon Cole

The Rio Olho d’ Agua is a spring-fed river in the southwestern Bonito region of Brazil and is home to more than 60 species of fish.

Brandon Cole

The Rio Claro — and just about every other river, pond and waterhole in the Pantanal — is filthy with the shifty-eyed reptiles. Some are skittish, but this 6-foot jacare caiman is bold — aggressive.

Brandon Cole

Arapaima, one of the largest freshwater fish, can also breathe air.

Brandon Cole

For divers used to the sea, exploring freshwater sites brings with it wild new ­creatures, new photo ­subjects, but also new challenges. Local guides can help navigate linguistic hurdles, keep you safe when it comes to potentially hostile natives (piranhas, caimans, bugs, etc.), and arrange travel, permits, access, and more.

Brandon Cole

Green-winged macaws are one of Brazil’s nearly 1,000 macaw species.

Brandon Cole

The Pantanal is the world’s largest wetland, so even though our regs are on holiday, we’re still in contact with água doce.

Brandon Cole

Noble jaguars — normally very reclusive — are often sighted along the banks of the Cuiaba river, and we are lucky to spot many peering out from the dense foliage, lazing along water’s edge.

Brandon Cole

Giant river otters that can grow to up to six feet long in the Rio Olho d’ Agua.

Brandon Cole