Hokkaido to Aomori

Did someone ever manage to hitch a (boat)ride from Hakodate to Oma?

It seems that the cheap ferry tickets have to be booked quite a lot in advance.

I don’t like to plan that far ahead, so I was thinking maybe to try and hitch a ride with a fisherman or something like that.

It also seems a cheaper ticket if you can join someone with a car.

Let me know if you tried this!