Genkainada Sea Route — Ferry to Iki Island

Iki Island, accessible by ferry from Karatsu or Hakata, is a 138-square-km island in the Genkai Sea with exceptional archaeological significance (it was the center of the ancient Iki-koku kingdom described in 3rd-century Chinese records) and excellent coastal diving. Most importantly, it is reachable from Karatsu as a day trip, and offers an island pace, clear water, and extraordinary seafood at prices that reflect the absence of tourist infrastructure rather than any lack of quality.