Pressure is mounting on the Government to bring in tougher laws and enforcement for coastal shipping in order to prevent another Rena disaster.
The Labour Party and the Maritime Union say regulations for offshore activity need to be enforced to prevent future incidents.
Coastal shipping is mainly carried out by overseas vessels carrying cargo, containers, fuel, logs and vehicles.
Maritime Union general secretary Joe Fleetwood says dedicated shipping lanes and New Zealand health and safety rules may prevent any wrongdoing.
Labour's transport spokesperson Phil Twyford says given the Government is tightening laws on foreign fishing vessels, it should also take a stance on coastal shipping activity.
Transport Minister Gerry Brownlee says the Government is waiting for various reports into the Rena and other incidents before making any concrete decisions.
The container ship ran aground on Astrolabe Reef, off Tauranga, on 5 October last year shedding tonnes of oil and debris and causing widespread pollution.
The ship's captain and navigation officer have been jailed for seven months for operating a vessel in a way which causes unnecessary danger and attempting to pervert the course of justice.