Yip No lisence required.
But us locals may require all tourists to undergo an initiation before we show you our top secret dive spot. I should point out our spot is so secret that it's listed in the places to dive/fish hand book available from any good book shop here in NZ.
Tell anyone where you dived and we may have to dispose of you
You should definatly check out the east coast of the south island when you come over.
North of Chch is a place called Kaikoura. One word describes the diving at this place when conditions are right. AWESOME.
For breathtaking scenery for lookie lookie diving. I've been told (by a pretty reliable source aka my father) that Milford sound is the place to dive. (although it's no where near chch, and not on the east coast)
Flick me a PM closer to the time when you come over and I may be able to (depending on exactly when you're over) arrange a non-charter, take you to the real spots dive with my Dad and our crew of scallywags down south. Look up Moeraki on a tourist NZ website to get an idea of where I'll be diving over summer, the reef is about 7miles off the coast.