The diver who went missing at the north-west end of Mana Island yesterday is Robert Hohepa Hewitt, 38, of Palmerston North.
Mr Hewitt's diving buddies raised the alarm at about 2.30pm yesterday after he failed to surface.
A sea and air search of the immediate area yesterday afternoon was unsuccessful.
Today's search area has widened to include a large area to the west of Kapiti Island and other areas around Mana Island.
Ground searches are also covering the coast around Pukerua Bay. Mr Hewitt, a former navy diver, is brother of former All Black, Norm Hewitt.
A media briefing by search coordinators will be held at the Kapiti boating club, intersection of Manly Street and Marine Parade, Paraparaumu at 4.30pm. Family spokesperson, Norm Hewitt, will also be in attendance.
Contact for further info: Debbie Corney (027)43 55 005 or AHrs pager (026) 10 10 82