Pius "Mau" Piailug (pronounced /ˈpaɪəs ˈmaʊ piːˈaɪləɡ/; 1932 – 12 July 2010) was a Micronesian navigator from the Carolinian island of Satawal, best known as a teacher of traditional, non-instrument wayfinding methods for open-ocean voyaging.

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).

To academia, Mau's achievement provided evidence for intentional two-way voyaging throughout Oceania, supporting a hypothesis that explained the Asiatic origin of Polynesians.

It contributed to the emergence of the second Hawaiian cultural renaissance and to a revival of Polynesian navigation and canoe building in Hawaii, New Zealand, Rarotonga and Tahiti.

He received an honorary degree from the University of Hawaii, and he was honored by the Smithsonian Institution and the Bishop Museum for his contributions to maritime history.

Mau's life and work was explored in several books and documentary films, and his legacy continues to be remembered and celebrated by the indigenous peoples of Oceania.

Mau's personal connection to the sea began early in his life, when he was placed in tide pools in his infancy so he could feel the pull of the ocean.

[3] Mau initially protested his grandfather's teaching, preferring to spend his time playing on the beach with children his own age.

Raangipi told the young boy that if he chose to become a navigator, Mau could gain respect from his community, eat well, and maintain a position in Satawalese society higher than that of a chief.

Later, Finney suggested to the Polynesian Voyaging Society that they should try to recruit Mau for their Hōkūleʻa project,[3] since no Hawaiian traditional navigators remained.

In addition, to alert Mau of how the elevation of stars above the northern and southern horizons would change as the canoe sailed farther and farther south, we held training sessions in Honolulu's Bishop Museum planetarium to graphically show how, for example, as one sailed toward Tahiti[,] Polaris sank lower and lower on the northern horizon until it disappeared at the equator while the Southern Cross curved higher and higher in the sky.

It marked the first time in over 500 years that a Native Hawaiian had mastered the stars, the seas, the birds, and the winds to guide a sailing canoe from Hawaii to Tahiti and back.

Describing a ceremony held at Waitangi to commemorate the Hawaii New Zealand voyage of Hōkūleʻa, Nainoa writes: Sir James Henare, the most revered of the elders of Tai Tokerau, got up and said, "You've proven that it could be done.

[37] To help preserve Hawaiian culture, Milton "Shorty" Bertelmann and his brother Clay established the nonprofit organization, Nā Kalai Waʻa Moku o Hawaiʻi[39] on the island of Hawaii in 1992.

Five Native Hawaiians and eleven other people were inducted into pwo as master navigators, including Nainoa Thompson and Mau's son, Sesario Sewralur.

[42] After a long struggle with diabetes, Mau died on his home island of Satawal at 18:30 Micronesia time,[43] Monday, 12 July 2010.

[47] Because there is no morgue on the island, Mau was buried the following day, and a nightly rosary was held until the memorial service on 21 July at Santa Soledad Church.

At the ceremony, secretary Lawrence M. Small said, "The rebirth of non-instrument navigation came about largely due to this man, Mau Piailug".

Mau also was honored for his "devotion and outstanding civic leadership" and for exemplifying "the spirit and purpose of the Museum's founder Charles Reed Bishop".

[50] The Polynesian Voyaging Society recognized Mau's contributions in preserving the art of wayfinding by building and donating the voyaging canoe Alingano Maisu to Mau and the people of Satawal, and he is honored with his name carved into the rail aboard Hōkūleʻa behind his traditional seat on the port rear quarter of the vessel.

The success of Mau's navigational feats sparked cultural pride in Tahitians, Māori, and Hawaiians and connected all Polynesians to stories their forebears told of similar voyages of generations past.

[54] Norwegian ethnographer Thor Heyerdahl hypothesized that the Pacific was settled by voyages from South America and set out to prove that with his Kon-Tiki expedition.

[56] Sharp granted that Polynesians likely settled the Pacific from Asia, but held the opinion that their crude vessels and navigational tools were not reliable for intentional sailing from Tahiti to Hawaii or New Zealand.

Examples of physical signals include the color, temperature, and taste (salinity) of seawater; floating plant debris; sightings of land-based seabirds flying out to fish; cloud type, color, and movement; wind direction, speed, and temperature; the direction and nature of ocean swells and waves; the position of stars in the sky, and his estimation of the speed, current set, and leeway of his sailing craft.

This mental model would have taken years of study to build; dances, chants (rong),[66] and stories helped him to recall complex relationships of geography and location.

Apart from the bulk of training, which happens at sea, historically boys were taught in the men's house with pebbles, shells, or pieces of coral, representing stars, laid on the sand in a circular pattern.

Swell patterns of prevailing trade winds are represented by sticks (not depicted here) overlaying the star compass in the form of a square.

It is a refined system of dead reckoning whereby the navigator constantly synthesizes his position relative to the reference island's location in his mental model.

Through Crux's longest axis, an imaginary line bisecting Gacrux and Acrux points southward toward the southern celestial pole.