Yes, estuarine (saltwater) crocodiles are native to the Tropical North Queensland region and are frequently sighted in the waters and on the beaches around Cairns. While attacks are statistically rare, "salties" are highly mobile predators that inhabit estuaries, rivers, and open coastal waters. Local authorities and the Queensland Parks and Wildlife Service actively monitor popular swimming spots and will close beaches if a "croc" is spotted nearby. Visitors must adhere to the "Crocwise" safety guidelines: only swim at beaches with active lifeguard patrols and stay within the designated seasonal "stinger nets," which provide a minor visual deterrent though not a physical barrier against large reptiles. It is especially dangerous to swim at dawn, dusk, or night when crocodiles are most active. Many locals and tourists prefer to swim in the Cairns Esplanade Lagoon, a massive man-made saltwater pool that is completely crocodile-free and patrolled year-round, offering a safe alternative to the beautiful but wild coastal waters where these prehistoric predators roam.