Hawai'i turns Ocean tiles from empty space into a genuine Culture engine — the only Exploration civilization built to treat natural disasters at sea as an opportunity rather than a setback.
"Moananuiākea" lets Hawai'i work Ocean terrain from the start, and grants Culture whenever a Storm, Flood, or Volcanic Eruption adds fertility to a tile — turning disasters other civilizations dread into a repeatable Culture source. Later tiers add Happiness and Culture on all Marine terrain and increased Production toward the associated Wonder.
The Leiomano is a unique Infantry-replacement with increased Combat Strength against Infantry and Cavalry that also earns Culture from defeating enemy units. The Kahuna is a unique Missionary that can heal nearby units in addition to its normal religious role, making it useful to keep near your army rather than purely on conversion duty.
The Lo'i Kalo is Hawai'i's unique Improvement, granting Food, Production, and Culture from adjacent Farms; it must be placed on Grassland or Tropical terrain. The associated Wonder, Hale o Keawe, adds Culture and grants a bonus when completing a building on Marine terrain.