Viewed casually, an undersea reef appears to have masses of fish all milling about aimlessly. An alien visitor to a human city might make the same observation about humans.

But just like a human city, fish society is organised and structured. This film is an entertaining, informative, and beautifully illustrated guide for the armchair visitors to one particular “City under the Sea.”

By exploring the reefs around New Zealand’s spectacular Poor Knights Islands, Wade and Jan Doak help viewers get to know one of the world’s richest and most complex realms – where reef fish interact not only with their own species but with many other species as well.

Reefs are multi-level colonies where opportunities for life abound, and fish are the reefs most mobile and adaptable citizens.

Just as humans’ cities have areas for housing, business and commuting so do the cities under the sea. Just as we follow many occupations in our cities, so do the fish in theirs – even to having day shifts and night shifts. And in similar ways to us, fish lead their private lives – with equally zealous competition for prime real estate, with courtship and mating rituals as strange as our own, and with similar responsibilities of raising young.

This is an intimate view of the patterns of life within fish society by day and by night, and season by season throughout one whole year.

City Under the Sea is a companion to Masters of Inner Space, which revealed the wonders of fish design. Both films are visually stunning and full of fascination. Together they are an exciting introduction to Wade Doak’s world of fishes.