"The Orion crew has covered around a quarter of the western area of the search zone. Meanwhile Kiribati authorities have arranged for a local vessel, the MV Tekokona, to conduct surface searching, and an Air Kiribati aircraft is expected to join the search on Sunday local time.
"This ferry has been overdue for a week, and the RCCNZ received a request for aerial assistance yesterday. Rescue services have had no communication from the crew.
"We are relying on our drift predictions to narrow down the search area as much as possible to increase the chances of finding their location as soon as we can," Ashby said.
"Maritime Radio here in New Zealand and in Tarawa is broadcasting for any vessels in the area to be on the look-out. Seas are moderate to rough, and the weather partly cloudy with some rain."