As early as 1523, Spanish explorers were sailing the southeastern coast of North America in search of potential settlements. By 1565, the Spanish had settled in St. Augustine, Florida, and were pushing up the coast establishing and maintaining additional colonies. Concurrent with these 16th-century ambitions for settlement, the French also made attempts at colonization in South Carolina Lowcountry areas. By the mid-1600s the English began to explore the southern coast. Prosperous Caribbean planters sponsored several expeditions to South Carolina. Captain William Hilton and Robert Sandford both made voyages to Port Royal Sound and vicinity. In July 1666 Sanford entered Calibogue Sound between Hilton Head and Daufuskie.