San Carlos is a beachfront subdivision within the port city of Guaymas, but is considered its own town in the northern state of Sonora in Mexico. It is known for the clarity and warmth of the ocean water in its shallow bays. It lies on the Sea of Cortez. Given the size of the city, with nearly 7,000 inhabitants, there is a large number of RV Parks, resorts and stores available. There is also an active diving community. Many Americans and Canadians live in San Carlos during the winter months.