Pius "Mau" Piailug (pronounced /ˈpaɪəs ˈmaʊ piːˈaɪləɡ/; 1932 – July 12, 2010) was a Micronesian navigator from the Carolinian island of Satawal, best known as a teacher of traditional, non-instrument wayfinding methods for deep-sea voyaging. Mau's Carolinian navigation system—which relies on navigational clues using the sun and stars, winds and clouds, seas and swells, and birds and fish—was acquired through rote learning passed down through teachings in the oral tradition.