Island Bay is a coastal suburb of Wellington, the capital of New Zealand, situated 5 km (3.1 mi) south of the city centre.

Cook Strait separates the North and South Islands of New Zealand. The strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast. It is 22 kilometres (14 mi) wide at its narrowest point, and is considered one of the most dangerous and unpredictable waters in the world. Regular ferry services run across the strait between Picton in the Marlborough Sounds and Wellington.