Marley, 17, was last seen in the Opawa suburb on 26 September. His car was later found in Sumner.
Police recently released CCTV footage which showed the teen wearing a light grey Adidas hoodie with white and black lettering, black shorts, black socks and burgundy Converse shoes.
Police, Land Search and Rescue, Coastguard Sumner, Fire and Emergency New Zealand, Surf Lifesaving New Zealand and volunteers have been searching for Marley in the Scarborough area and surrounding bays.
Boats, drones and now a helicopter are being used in the search.
Police have asked the public to stay away from the Scarborough and Godley Head areas "while operations are in place, in order to ensure safety".
Police said to call 111 - quoting the reference number 250927/3331 - if Marley is sighted.
