The kariba ferry sailing dates and prices you see on our website are up to date and current. Being a single traveller I can't think there would be a problem for you to get on.
Your major problem I would think is getting from Mlibizi where the ferry docks to Victoria falls. This is a distance of about 300kms and there is no form of scheduled transport.
People are either travelling in their own vehicles or they arrange a transfer with one of the transfer companies in Vic Falls. These transfers though are charged out to a minimum of 4 pax at $82 each.
You can maybe try and hitch a ride with someone. There is no other boat service that operates from one end of the lake to the other, it is a distance of nearly 400kms, so hiring your own boat would cost an absolute fortune.
