Just offshore from New Plymouth lies the remains of an ancient volcano much older than Mt Taranaki. This group of low sea stacks and seven islands provide a unique semi-sheltered environment along an otherwise exposed coastline.. The best places to dive are found in and around these volcanic islands where many underwater outcrops and canyons can be found. The islands are a marine protected area.
Both Oakura, Opunaki and many other black sand beaches along the Taranaki coast have shallow volcanic reefs, large boulders and lava flows that extend out. They are inhabited by common reef fish, crayfish and paua.
North of Opunaki, at in Namu Bay you can dive the wreck of the Lord Worsley in shallow water. The dive provides you with a view of the scattered iron plates of the steamer that went agound at 1.30 a.m.on September 1, 1862.
The remains of the iron barque Northern Monarch wrecked November 7, 1903 can be seen north of the Oaonui Stream.
There are several reefs off Opunaki with abundant see life and good diving. The Waitotara and Patea Reefs are known to be some of the best cray diving sites in the north island of New Zealand.