Carolinian is an Austronesian language spoken in Northern Mariana Islands, where it is an official language along with English and Chamorro. Spoken mostly by the Carolinian people, Carolinian is most closely related to Satawalese, Woleaian, and Puluwatese. Carolinian has 95% lexical similarity with Satawalese, 88% with Woleaian and Puluwatese; 81% with Mortlockese; 78% with Chuukese, 74% with Ulithian. A 1990 census estimated the number of speakers at about 3,000, currently 5,700. Carolinian is known as Refaluwasch by native speakers. It has 31 characters in its alphabet.

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. He earned the title of master navigator (palu) by the age of eighteen, around the time the first American missionaries arrived in Satawal. As he neared middle age, Mau grew concerned that the practice of navigation in Satawal would disappear as his people became acculturated to Western values. In the hope that the navigational tradition would be preserved for future generations, Mau shared his knowledge with the Polynesian Voyaging Society (PVS). With Mau's help, PVS used experimental archaeology to recreate and test lost Hawaiian navigational techniques on the Hōkūle‘a, a modern reconstruction of a double-hulled Hawaiian voyaging canoe.