Moana's Boat is one of the boats that Moana's ancestors sealed away when the ocean became too dangerous to sail on, and the one that Moana used on her journey to find Maui and return the heart back to Te Fiti.
Not long after the demigod, Maui stole the heart of Te Fiti and Te Kā unleashed a curse that was killing islands and making the ocean too dangerous to sail upon, all the boats that Matai Vasa and his people used to sail and discover Motunui were sealed away. Including one small sailboat, with a red spiral on its sail.
Years later, when Tala led her granddaughter to the sealed cave, Moana discovered the small boat and played on it a bit before she went to play the drum. After Tala's death and when Moana understood what she must do, she returned to the cave, measured the mark on the gem with the mark on the boat's sail, she sailed it through the waterfall and beyond the reef as her journey began. With Heihei as a unknown passenger in the boat's cargo hold.
Not long after finding the island that Maui was trapped on, the demigod tried to steal it so he could escape the island; and the Ocean helped Moana get back onboard it, so they could venture to the Mother Island together. On the way to Lalotai - so they could retrieve Maui's Fish Hook - the fallen demigod taught Moana how to sail her small sailboat, with the art of wayfinding; and once Maui re-mastered his shape shifting powers they made their way to Te Fiti. The skilled that Moana gained from sailing it, helped her to become a master wayfinder; like their ancestors before her.
The boat's sail was damaged in Moana and Maui's first round with Te Kā and not long after Maui left Moana and Tala's ghost came to comfort her granddaughter, it was surrounded the ghost sailboats that were steered by the ghost of Matai and his people. With Moana's hope restored she repaired the sail and made her way back to Te Kā. In the second battle, the boat was destroyed when Moana reached Te Fiti's island, and after the heart was returned to the goddess and Te Fiti lifted the curse of Te Kā, she used her power to recreate the boat so Moana could sail home.