We will only travel on Interislander now for the ferry. Highly recommend this ferry service over Bluebridge. The interislander boat Kaitaki is the best if you are travelling with Kids. It has more to do and a really large 2 story playground. We found the service very reliable and food options are good and reasonable in price. Plenty to see and do on board. If you don't want to pay for the cost of your trip all up I recommend using "cruisy pay" where you pay off the trip with no interest charged in equal installments before you go up to 12 months in advance. There is easy options to change bookings if need be sometimes without extra cost. The Kaiarahi is a really nice boat. Not as much to do on board for the kids and the play area on that one was really lame in comparison to the Kaitaki but we highly enjoyed our trips across the straight with interislander. Awesome service on both ships. We hired a cabin for $30 on the Kaiarahi. Was clean and comfortable. Free wifi on board.