Pelorus Sound / Te Hoiere is the largest of the deep, flooded river valleys that comprise the Marlborough Sounds at the north of New Zealand's South Island. This extensive saltwater sound is characterized by a complex network of sheltered bays, inlets, and channels, with steep forested hillsides descending directly into the sea. The landscape is a result of rising seas and a sinking landmass over millions of years, creating a deeply indented coastline that provides excellent shelter from the open waters of Cook Strait. The sound is remote and quiet, with access primarily by boat, and it supports a mix of recreational and commercial marine activities amidst a backdrop of significant historical and ongoing environmental change.