Australia NZ Inter Island Ferries

I am interested to find out one information. I looked and asked some people. I have problem because I cannot find information about Australia NZ Inter Island Ferries. Does somebody have information about this. I will cross from Australia to NZ with my car. Can someone give me information about this?

Hey. I crossed from Australia to NZ with my family by car. We used Interisland ferries. I think that it is much easier to travel with your own car trough NZ. I thought that it will best and most comfortable for my family. Because of that I was afraid for ferry ticket. I thought if I should by ticket in advance. But I decided to take a risk. Because it wasnt vacation time, or some holiday. I thought that there is no reason that all tickets would be sold. And I was right. We didnt have any problems in transport. So I suggest you not to worry. I heard one information that I dont know if it was true. I heard that if you bought ticket earlier there was some chance that you got better price. But I am not sure.