The main reason people come to Imbituba is the coastline, and it delivers. Praia do Rosa is the standout — a long arc of sand between two headlands, protected enough for swimming but with consistent surf that has attracted serious wave riders for decades. The village behind the beach has grown around that reputation, with small pousadas and surf shops, but it hasn't been overdeveloped. You can still walk the headland path and feel like you found it yourself.
Closer to town, Praia do Pinheira and Praia de Ibiraquera are quieter options backed by the Lagoa de Ibiraquera, a large coastal lagoon popular for windsurfing and kite surfing. The lagoon and beach share a narrow strip of land that makes the setting unusually scenic.
Praia de Itapirubá to the north is the most local of the beaches — families, fishing boats pulled up on the sand, not much infrastructure. A good place to go if you want fewer people.