The cheapest way to travel between the North and South Islands is usually booking a low-cost flight (typically Jetstar or Air New Zealand) between Wellington and Christchurch or Auckland and Christchurch. If you book in advance, one-way fares can be as low as $45–$60 NZD. In contrast, the famous Interislander or Bluebridge ferries crossing the Cook Strait usually cost around $65–$75 NZD for a foot passenger. While the ferry is one of the most beautiful boat rides in the world, it is rarely the absolute "cheapest" unless you are part of a group sharing a vehicle, as transporting a car on the ferry can cost $180–$250 NZD. However, many budget travelers choose the ferry because it saves on the cost of a rental car "one-way fee" if they are driving the same vehicle across both islands. If you are a solo traveler with just a backpack, a "Grabaseat" deal on a flight will almost always beat the ferry price, but you'll miss the stunning views of the Marlborough Sounds.