boat from China to Okinawa

Hi there,
This summer I am making a trip from europe till Japan. I'll be visiting Russia, Mongolia and China. Then I'll be studying in Tokyo.
I am making this trip with two other friends, and we were wondering if there was any way to take a boat from mainland China (or Taiwan) to Okinawa. I could'nt find much of information about it, so maybe someone here could give me some directions.
The purpose of taking the boat is just that I assume that it would be cheaper than plane...
Thanks in advance.

Alex

There used to be a regular ferry between Taiwan and Okinawa, but it went bankrupt about two years ago. So, unfortunately there are now no more regular boat connections between China/Taiwan and Okinawa.

But I think there are irregularly operated cruise ships. Not sure whether they can be used for a one way trip, though.