The problem from Jinan to Jeju Island! ! ~~~

By boat? Can't you? In addition, flying is also very convenient. Why take a boat?

You don't need a visa to go to Jeju, but you must have a round-trip air ticket and a hotel check-in certificate when you go through customs.

You can exchange money after you go, and it will be more cost-effective to bring dollars.

There's nothing special to know. It is better to know some Korean, but it doesn't matter if you don't know it at all. There are Japanese signs everywhere. You can look at them and guess the meaning close to Chinese, and there are also English signs. There are quite a few people who know Chinese, so don't worry about communication.