Inner Sea tours

At one part of my trip I will be in Okayama/Hiroshima. I would love to do a day tour of the Inner Sea. Are there any operators in either of these two cities? Do they have a link you can post?

Thank you

It is usually refered to as Seto Inland Sea or Seto Naikai.

I am not aware of any sightseeing cruises, but there are many regular ferry lines criss crossing the sea. So, it would be possible to do some island hopping.

Around Okayama (岡山):
http://www.fune.co.jp/J-index/Z-teiki/Z-KOURO/Z-04-01.html

Around Hiroshima (広島):
http://www.fune.co.jp/J-index/Z-teiki/Z-KOURO/Z-07.html

Alternatively, riding a bicycle from Onomichi in Hiroshima Prefecture to Imabari on Shikoku seems to be a nice way to see some Seto Inland Sea scenery:
http://www.jnto.go.jp/eng/location/regional/ehime/shimanamik...
http://www.wel-shikoku.gr.jp/eng/seto/cycling.htm
http://www.go-shimanami.jp/