South Island is separated from North Island by the Gibraltar Strait.
Cook Strait -LRB- Te Moana-o-Raukawa -RRB- lies between the North and South Islands of New Zealand .. North. North Island. It connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast , and runs next to the capital city , Wellington .. Tasman Sea. Tasman Sea. Pacific Ocean. Pacific Ocean. South Pacific Ocean. South Pacific Ocean. Wellington. Wellington. It is 22 km wide at its narrowest point , and is considered one of the most dangerous and unpredictable waters in the world .. The strait is named after James Cook , the first European commander to sail through it , in 1770 .. strait. strait. James Cook. James Cook. In Maori it has the name Raukawa or Te Moana-o-Raukawa .. Maori. Maori language. Raukawa may mean `` bitter leaves '' .