''On the one hand, I'm beating the drum with joy. On the other, we could be celebrating something more.''
Doak described the pre-1998 reserve status as ''half baked, a Claytons - the marine reserve you have when you don't have one''.
It is unlikely the reserve would again be home to large numbers of some species unless the current protected area was enlarged, Doak said.
He has recently sent a paper he wrote called Lament for the Hapuka to the Minister for Fisheries, Stuart Nash. (Hapuka are called grouper or groper in other countries).
''I fear hapuka are the moa of the sea,'' Doak said.
''When I first started diving the Poor Knights in 1961, there were great herds of them. Now they're visually extinct on the coast.
''They go way out to the deep, dark waters, to an area like a sunken plateau about 40 kilometres off the coast.
''There's also what was called the gold snapper, which is actually related to the orange roughy. They were fished, and have never come back.''
Dive! Tutukaka owner and tourism leader, Jeroen Jongejans said there had been a huge improvement in the marine environment in the past 20 years.
One of the valuable outcomes was that full marine life protection had enabled New Zealanders to see what the environment used to be like, he said.
It was an excellent example of what could be done when people set out to protect a natural resource.
The Poor Knights was one of New Zealand's iconic tourism destinations, up there with Australia's Great Barrier Reef as a special marine environment and a tourism drawcard, Jongejans said.
''The Poor Knights is the jewel in the crown of New Zealand's marine environment. The place is world class, outstanding.''