The nature of Elvis Teddy's defence on charges arising from a Greenpeace protest at oil exploration of the Raukumara basin is emerging in the defence cross examination of police witnesses.

The 44-year-old was the skipper of the fishing vessel San Pietro when police boarded the vessel and arrested him on April 23 last year during a protest in front of the Petrobras oil exploration ship Orient Explorer.

The Petrobras oil exploration ship Orient Explorer during the protest off the East Cape. Photo: Greenpeace.

The 4-5000 tonne steel ship Orient Explorer was towing a16km long sonar array, while Elvis was positioning the wooden hulled 40-50ft fishing boat off its starboard bow.

Elvis is defending a charge in Tauranga District Court this week under the Maritime Transport Act that he operated a ship in an unsafe manner, and with resisting arrest. He's facing a possible 12 month jail sentence or a $10,000 fine on the MTA charge.

Police say they boarded Elvis's boat because he was operating within the exclusion zone announced the day before, and that he endangered people with his close approaches to the Orient Explorer.

The defence is arguing fishing boat skipper Elvis Teddy kept his boat in a safe position off the bow of the global explorer and that the San Pietro only crossed the Orient Explorer's path after police arrested Teddy and took over the wheel.

In cross examination of the senior police officer in the boarding party today, Teddy's lawyer Ron Mansfield asked about precise details of where the fishing vessel San Pietro was positioned during the boarding process.

Referring to still photos and video taken from the bridge of the Orient Explorer, he repeatedly questioned the difference between the police view of the San Pietro's behaviour and whether it could be that Teddy was holding the San Pietro in position off the starboard bow of the exploration ship, and that the San Pietro only crossed the Orient Explorer's bow, cutting it off when police boarded and arrested him.

Elvis Teddy outside Tauranga District Court.

The police officer stated police were concerned for safety with the San Pietro slowing as it crested the less than two metre swells, but the much large exploration ship was not.

He thought the larger ship would 'just run over” the fishing boat.

The Orient Explorer's speed was estimated between 4-5 knots.

Suppression orders prevent the naming of the officer under cross examination and also prohibit details about the command structure and information about how the orders were relayed during and after police boarded the San Pietro.

The officer also said that while Elvis repeatedly swore at police aggressively, and gesticulated before they boarded, he offered no resistance when police boarded the San Pietro.

At one stage prosecutor David Pawson wanted the police officer to sketch out a ship shape and enter the terms bow stern, port side starboard side on it, because he was concerned the case could turn into a semantic argument over nautical terms.

Judge Patrict Treston, an experienced ocean sailor, stated he is not confused.

'The sharp end is the bow the blunt end the stern, starboard is right port is left,” says the Judge.

The trail continues.