There are several places called Blanket Bay:
In Australia Blanket Bay (Victoria), in Great Otway National Park
In New Zealand Blanket Bay (Otago Harbour), located south of Port Chalmers in Otago Harbour Blanket Bay (Lake Wakatipu), located close to Glenorchy, Otago Blanket Bay, at the southern tip of Secretary Island in Doubtful Sound, Fiordland