The Polynesians used double-hulled canoes not rafts. King Kamehameha conquered the Hawaiian island using giant canoes with accounts from Westerners. The system

The Polynesians used double-hulled canoes not rafts. King Kamehameha conquered the Hawaiian island using giant canoes with accounts from Westerners. The system of navigation was recorded orally. People in living memory retained the knowledge. Anthropologists got it from them, built replica canoes, and then sailed around discovering that it worked. Captain Cook used Polynesian navigator who was well traveled. Maybe the rafts are coming from Easter Island losing the technology and using rafts instead.