You Do Need power plug adapter while traveling from Antigua and Barbuda to Norfolk Island.

Here is Why You Need An Adapter

The outlet and plug type used in Norfolk Island is I and in Antigua and Barbuda are A and B. This is how they look like.

Antigua and Barbuda

In Antigua and Barbuda, outlets of type A and B are in use.

Type A

Type B

Norfolk Island

In Norfolk Island, outlets of type I are in use.

Type I