Te Aumiti / French Pass is a narrow and treacherous stretch of water that separates D'Urville Island, at the north end of the South Island of New Zealand, from the mainland coast. At one end is Tasman Bay, and at the other end the outer Pelorus Sound leads out to Cook Strait.

French Pass has the fastest tidal flows in New Zealand, reaching 8 knots (4 m/s).[1] When the tide changes, the current can be strong enough to stun fish.[2] The local tribes are Ngāti Koata and Ngāti Kuia.
(Wikipedia)