Japan:
1,770 km approximately
note: seagoing craft ply all coastal inland seas
Jarvis Island:
none
Jersey:
none
Johnston Atoll:
none
Jordan:
none
Juan de Nova Island:
none
Kazakhstan:
3,900 km
note: on the Syrdariya (Syr Darya) and Ertis (Irtysh) rivers
Kenya:
NA