Greenpeace boss Russel Norman faces more weeks of waiting to find out if he'll be punished over oil exploration ship protest

Greenpeace executive director and former Green Party co-leader Russel Norman will have to wait longer to find out how and if he'll be punished for putting himself in the way of an oil exploration ship.

Dr Norman and Greenpeace volunteer Sara Howell were the first to be charged under controversial legislation effectively banning people from protesting in front of ships.

The law-change passed in 2013 became known as the so-called "Anadarko Amendment".

The pair swam in front of the Amazon Warrior, a seismic survey ship, off the Hawke's Bay coast.

Greenpeace argued the protest was because such surveying is damaging to marine life, and because any oil find could have resulted in deep-water drilling.

The pair faced a year in jail and $50,000 in fines at today's sentencing in the Napier District Court.

But the judge delayed today's sentencing, telling the court he'd endeavour to make a decision before September 24th.

Dr Norman and Ms Howell's lawyer Ron Mansfield argued for a discharge without conviction, arguing the right to protest is an important element of democracy.

"The court should seriously consider the culpability of the defendants and their intentions, and ask itself whether a conviction should be imposed because of the negative impact that a conviction might have on our community to raise issues in a similar way," Mr Mansfield said.

That argument was opposed by the Ministry of Business and Enterprise (MBIE).

Supporters cheered as the pair left court.

In a statement given to 1 NEWS before today’s sentencing, Norman said he had no choice but to confront the world's largest oil and gas exploration ship.

"As seas rise and extreme weather events become more frequent, we're facing the reality that if we delay action any longer, the worst impacts of climate change for us and our kids will be unavoidable," he said.

Before Norman and Howell were charged, the only other breach of the amendment to the law change was a Greenpeace vessel breaching a zone around a drilling ship off Taranaki in 2013.

Four crew members were given formal warnings.