During your short journey through Breaksea Sound and Acheron Passage, you have seen a sound, passage and arm. What’s the difference? Nothing. All of these U-shaped seawater valleys were carved by glaciers over 100,000 years ago. This technically qualifies them as fjords and not sounds which are sunken river inlets. And New Zealanders prefer the word fiord versus the Norwegian spelling of fjord. Confused? So were Captain Cook and his men so blame them for the misnomers.
