Prince Rupert Bay stretches south from the Cabrits peninsula for several kilometres, offering calm, protected swimming in clear water. The bay is named after the 17th-century English admiral and privateer Prince Rupert of the Rhine, though its strategic value was recognised long before the British arrived — it can shelter a large fleet in near-complete calm, which made it repeatedly contested during the colonial era. Today the only traffic is fishing boats, the occasional cruise ship anchoring offshore, and the small boats of Indian River guides heading back and forth.
The beach south of the town centre — sometimes called Purple Turtle Beach — is the most accessible stretch. The sea is usually calm and suitable for children. A small reef section south of the Cabrits headland is worth snorkelling if you have gear; you'll see parrotfish, trumpetfish, and smaller reef species. The bay faces west, so sunsets are good.