Towadako ferry on March 2012

Hi,
I'm planning to go to Towadako as a daytrip on March, as using the JRPass I can take for free the bus from Hachinohe to Towadako, I want to do this:
10.00 JRTohoku Bus Hachinohe-Towdako, arriving at 12.15
15.30 JRTohoku Bus Towdako-Hachinohe, arriving at 17.45
My question is; Can I take the Ferry (round course) between 12.15 and 15.30.
Does anyone have the timetable for this March?
Any information is appreciated...

Here is the winter timetable which will be in effect until March 31, 2012:
http://www.lakeship-towada.co.jp/actual3003.html

There are round trip departures at 9:00, 10:00, 12:00 and 14:00.

Thank you Uji for your answer... now I have another one. Do you know how far is the the ferry terminal from the JRTohoku bus stop on Yasumiya?

Just a few steps.