Maritime New Zealand's current online services.
For some classes of vessels, it will be compulsory to carry registered 406 MHz EPIRBs from 1 July 2008.
To determine if that applies to you, please contact your nearest MNZ advisor or check out the relevent rules on the website:
EPIRB Amendment document [PDF: 215Kb, 10 pages]
Basically, if you are currently required to carry a 121.5 MHz EPIRB, then you will be required to upgrade it to a 406 MHz EPIRB by 1 July 2008.
For more information on beacons, check out the beacons website.
www.beacons.org.nz [Beacons.org]