The epic journey was accom plished with no navigational aids except those in the mind of her Polynesian navigator, Nainoa Thompson. To guide them across the vast Pacific, ancient navigators created a mental compass which helped oriend the ship to the rising and setting points of the stars. Nainoa Thompson developed a Star Compass, which features 32 equidistand points around the horizon. Celestial navigation is a method used usually out in the open sea. The navigator makes use of the celestial bodies that were identified and grouped into constellations in ancient times.
Celestial navigation makes voyages of a thousad miles in unmarked waters possible.
Its only disadvantages is that many elements can reduce your vision of the stars such as clouds, fog, mist, or haze etc. The stars rise and set in particular directions at the horizon. For example, a star rises in the northeast horizon, travels across the sky and sets in the northweastern horizon. The rising and setting points of the stars are a clue to the direction. The Hokule'a's voyage to Rapa Nui was one of its longed and most difficult journeys.