Transverse Mercator projections have limited longitudinal extents therefore separate projections have been defined for the Antipodes, Auckland, Bounty, Campbell Island / Motu Ihupuku, Chatham, Kermadec, Raoul and Snares Islands / Tini Heke Islands.

New Zealand has jurisdictional responsibility for a number of offshore islands. To facilitate the consistent topographic mapping and integration of spatial datasets a series of map projections has been defined.

These are all Transverse Mercator projections and are based on the NZGD2000 datum using the GRS80 reference ellipsoid. The distortion in transverse Mercator projections increases with distance from the longitudinal central meridian; consequently different projections have been defined for the different offshore island groups. The projections have been defined so that no two points on land will have the same numerical coordinates in terms of different projections.

The offshore island projections are formally defined in the LINZS25002 (Standard for New Zealand Geodetic Datum 2000 Projections). The key parameters from this standard are summarised below:

Projection type:Transverse Mercator
Reference ellipsoid:GRS80
Origin latitude / central meridan:0° 00' 00" South
False Northing:10,000,000 metres North
False Easting:3,500,000 metres East
Central meridian scale factor:1.0000
AreaProjection NameAbbreviationOrigin Longitude
Chatham IslandsChatham Islands
Transverse Mercator 2000
CITM2000176° 30' West
Snares Islands / Tini Heke and
Auckland Islands
Auckland Islands
Transverse Mercator 2000
AKTM2000166° 00' East
Campbell Island / Motu IhupukuCampbell Island
Transverse Mercator 2000
CATM2000169° 00' East
Antipodes and
Bounty Islands
Antipodes Islands
Transverse Mercator 2000
AITM2000179° 00' East
Raoul Island and Kermadec IslandsRaoul Island
Transverse Mercator 2000
RITM2000178° 00' West