The less than one kilometre wide Patea passage to the south of the island is the main entrance to Doubtful Sound.

The waters between the two islands are protected by the Te Awaatu Channel (The Gut) Marine Reserve.

Doubtful Sound tour boats routinely travel through this channel.

Bauza Island is uninhabited and named after Spanish naval officer Felipe Bauzá, the main cartographer of the Malaspina Expedition to the Americas, Oceania and Australasia between 1789 and 1794.

Even though the island is now pest-free, the traps need to be checked and re-baited periodically as stoats have been known to swim distances of over 1 kilometre (0.62 mi).