Hi there again.
The Naki can get very very wild most of the time. Lots of rocks and not only small rocks I mean bloody big rocks too.
It's great windsurfing with high winds and big waves, but only advance here kiters or go out on the few light wind days a month to get in to the grove of the place. It can get cold too.
Auckland in winter is a 3/2 steamer with a rash shirt some times where the Naki in about 5mm in winter with a rash shirt. Wellington just gets to cold and also has real high winds also.
There is some good west coast kiting off Auckland North and South with big long sandy beaches, no rocks.
I know that Raglans not bad, but you have to watch the the river rip down there. There is another good harbour below Raglan called Kafier I think, (Spelling not there but sounds like that)
which is a really nice spot for windsurfing and kiting.
Apart from that I do not know too much more about the west coast.
Hope this helps somewhat.
Pat J