The lake will likely be frozen. Boats and canoes do not operate in winter

They have individual and two person kayak, paddle boats for multiple people (if you are bringing your family), little boats with motors. The boat rides are pretty cheap ranging from 5,000 Won to 30,000 Won+

Was not aware board on lake.

I think it is called Lotte Mart. It is actually a very good size with several levels and many goods and services, including ramen noodles and eye care. It is just across the street from the Central Central Park. By now, the Park should have opened several more tea shops and restaurants that have adopted traditional Korean architecture. Have fun!!

Hi. You can take the taxi cabs that are at the gate and maybe negotiate with them to wait for you and bring you back to the airport. There might be available day tours for travelers with long layovers. Just approach their customer service desk. I hope this helps.

The rental area is at the east (south east) end of the river. Unfortunately, I do not know the name of the company.