John,
What momjaz wrote about Waitamata Harbour (Auckland) is really only half the story. NZ isless than a mile wide on the south edge of this harbour, and guess what, there's another harbour on the other side of NZ! - you'd love it.
In the same way, just north of the Auckland city limits to the west is the beautiful really black sand beach of Muruwai...and a few miles away on the east coast is a white sand one which is part of a terrific lagoon that is like an elongated 0 with just a small mouth open to the sea almost at one end. The fishing is fantastic - 4 of us caught over 200 in 7 hours. The first 5 bites I had all took and they were five different...including 2 rays. One of the blokes had a smoking shed and after quick gutting they were ''all fired up'', I've never had a day's fishing like that, and all in beautiful sunshine.
We also caught 4 Blow fish and puffer fish, they're 7-12'', mainly white and have spines that make them extremely poisonous. The drill when you can see that you've hooked one is to alert everyone to grab canvases/tarps/plastics and machetes and when everyone's ready, you bring it aboard as gently as possible, cover it and kill it, then swab the decks with 20+ buckets of water in case it's poison was ejected. They are really bad news. It really was a great day, and we had fish for weeks!!!