Tauranga mayor Stuart Crosby wants a thorough independent inquiry into the grounding of the Rena last year.
The Transport Accident Investigation Commission released its interim report on Thursday, in which it said the container ship did not follow its passage plan and took a series of short cuts before hitting the Astrolabe Reef.
Transport Minister Gerry Brownlee has ruled out a separate inquiry into the disaster and says he sees no need for maritime law changes.
Butr Mr Crosby told Radio New Zealand's Morning Report programme he wants to know whether past deregulation has put the coasts at risk and whether there are ways of making vessel passage safer.
Fatigue labelled possible factor
The organisation representing commercial ship captains and crew says fatigue among the crew members may have caused the Rena to run aground.
The TAIC report said the Rena was trying to make up a 13-hour delay when it struck the Astrolabe reef in October.
The President of the Merchant Services Guild, Lou Henderson, says international regulations governing how much sleep crew should get are not always followed.
Captain Henderson says the problem is becoming more common as companies hire crew who are less likely to complain about tiredness.
The Rena was owned by a Greek company and sailed by a Filipino crew.
