The coast boat trip is the best way to see Hongdo. Boats leave from the harbour and circle the island's roughly 21 km coastline, passing sheer cliffs, sea stacks, and the red-brown rock formations that give the island its name.
Go only if the sea is calm enough. On a good day, the boat trip is the reason to come; on a bad day, Hongdo can feel like a very small village at the end of a long ferry ride.