Notable beaches 

(A quick reference)

The common factor among these beaches is simply the high likelihood of finding other Naturists there, even during the week. 

Uretiti -  Whangarei 

Uretiti Beach is 35 km south of Whangarei, by the DoC reserve right next to State Highway 1. During summer there are generally good numbers of others to be found on the beach beside the DoC campground; weekdays included. There is now a new beach access just south of the camp gate - the best parking option.

St Leonards -  Auckland 

St Leonards Beach is just south of North Shore City's main Takapuna Beach. Special council rules may apply. (Essentially, it's just a matter of keeping at least 50m from the access steps, and not walking in front of passers-by.)
Since the council now allows dogs on this beach, there are quite a few more 'textiles' evident than there used to be.  

Ladies Bay -  Auckland 

Ladies Bay is in St Heliers: at the end of Tamaki Drive - go up Cliff Rd and park (if you can, there) and walk back to the path down the cliff to the beach. The council had set up an overlooking platform, but there's no sign that it has affected nudist numbers. However, the activities of one male oaf puts many women off! (So it is recommended only for those prepared!)

Papamoa -  Tauranga 

Papamoa Beach's 'nude zone' is directly behind the prominent signs in the dunes, about 1 km from the Mt Maunganui end of Papamoa Beach Rd (which is called Maranui Rd at at that end).
As at Uretiti and Breaker Bay, there are often people here on a week-day. The police patrol the dune area and may issue trespass notices to any-one found loitering there: a cause of justifiable complaint by everyone, in years gone by. (All okay otherwise.)

Breaker Bay -  Wellington 

Breaker Bay, at the entrance to Welling-ton Harbour, is in the suburb of Seatoun. This beach has a notable geographic feature which tends to set the theme: clothes-optional past the 'hole in the rock;' usually 'dressed' on the near side of it. From the car park there is a 70m trek to the rock through fine pebbles (there's very little sand here). One of the reasons for the popularity of this area is it's shelter from Wellington's prevailing nor-westerly. On a dubious day in town it can be very nice out there.

Heyders Rd Nth -  Christchurch 

The Heyders Road entrance is at the north end of Spencerville - walk about 200m. (The area looks rather similar to Northland's high profile Uretiti.)
Following liaison with the local authorities Christchurch Free Beach members have agreed to use this place (in preference to the nearer Waimairi Beach, due mainly to its unsavoury reputation). 
(The Beach Ambassador guide is there to address just this situation, but it has been quite rare for any volunteers to ask for one - it is free!)