UPDATED 4PM: In the hours leading up to the grounding of the Rena on Astrolabe Reef the ship's crew failed to comply with ‘basic principles of navigation', a court has heard.

The captain and navigation officer are being sentenced in Tauranga District Court today on a raft of charges relating to the grounding of the ship on the reef on October 5, 2011.

This morning a courtroom packed with media heard in the summary of facts how the crew made a series of changes to the ship's path to speed up the arrival time at the Port of Tauranga.

The Rena's captain and navigation officer in court today.

The summary reveals the Rena deviated from the passage plan travelling close to the submerged reef Bull Rocks, Arial Bank and the shallows of Arial Rock.

At one point the ship was 5.8 nautical miles off the approved passage plan.

At about 1.35am on October 5 the navigation officer altered the course of the Rena to 252° substantially deviating from the approved passage and putting Rena on track to hit the reef.

He then called the captain to the bridge and informed him of the change.

The court heard the crew then failed to record the change on the chart and no steps were taken to project Rena's forward course.

The summary states when the captain came onto the bridge he did not check the alteration of the course or the ship's position in relation to the passage plan. He also failed to transfer the ship's position to a larger and more appropriately scaled map showing navigational hazards including the Astrolabe Reef in more detail.

Approximately 10 minutes and 15 seconds before the ship grounded, the Astrolabe Reef appeared on the ship's radar.

At this time the ship was three nautical miles from the reef and on direct course to hit it.

The summary of facts reveals the Rena was 2.6 nautical miles from the reef when the captain noticed it on the radar and believed it was a small vessel or false echo.

The court heard that at no stage did the captain instruct any action to be taken to avoid colliding with the object on the radar.

The ship struck the reef at 2.14am.

Prosecutor for the Crown Rob Ronayne told the court each man's actions was 'incompetence verging on recklessness” and is seeking a jail sentence with a starting point of two years.

The court was told that after the grounding the captain instructed the navigational officer to alter the chart and the passage plan.

The captain also made a further addition to the chart to appear as though Rena was planning to pass clear of the reef.

The captain's lawyer Paul Mabey QC argued for home detention for his client.

'It was a hopeless case of a coverup.

'There is no evidence of recklessness.”

He also said the captain and crew of the Rena had identified the oil leak and were taking steps to stop it when the control of the ship was taken out of their hands.

Both the captain and navigational officer have pleaded guilty to the same charges under the Maritime Transport Act 1994 for operating a vessel in a manner likely to cause danger, under the Resource Management Act 1991 for discharging a contaminant and on three charges under the Crimes Act for altering ship documents.

The captain faces one additional charge under the Crimes Act for altering ship documents.

During a court appearance in February, the Rena captain pleaded guilty to all charges for his action as a master of the container ship on the night it ran aground.

The charges under the Crimes Act each carry a maximum penalty of seven years imprisonment.

The navigation officer previously pleaded guilty to a charge laid against him under the Maritime Transport Act and to three charges laid against him under the Crimes Act.

He today pleaded guilty to the charge laid under the Resource Management Act for discharging a contaminant.

The RMA charge carries a maximum penalty of a fine of $300,000, or two years imprisonment and $10,000 for every day the offending continues.

The Maritime Transport Act carries a maximum penalty of $10,000 or a maximum term of imprisonment of 12 months.

Representatives for the owners of the ship, Greek shipping company Daina Shipping, also facing two charges under the Resource Management Act.

The RMA charge is under section 338 (1B) and (15B) relates to the ‘discharge of harmful substances from ships or offshore installations'.