The waters around Imbituba are one of the most important calving grounds for southern right whales in the entire South Atlantic. Between May and November, the whales migrate north from Antarctic feeding grounds to give birth and nurse their calves in the sheltered bays along this stretch of coast. The peak is July and August, when it is not unusual to see multiple whales from a single headland in a single morning. What makes Imbituba unusual among whale-watching destinations is that you don't need a boat — the whales come close enough to shore that watching from the rocks is often as good as any boat trip.
The headlands around Praia do Rosa and Praia de Ibiraquera are the best vantage points for shore-based watching. Boat trips are available if you want to get closer, but they are regulated to avoid disturbing the animals. The whole area falls within a marine protected zone during the season, and there is a Brazilian research project — the Projeto Baleia Franca — that has been monitoring the population here for decades. The whales are recovering: numbers have grown steadily since protection began, which makes this one of the relatively hopeful conservation stories on the South American coast.