The Transport Accident Investigation Commission has completed its inquiry into the Rena grounding and will release its final report later today.

A press conference will be held at the Tauranga Yacht and Boat Club at 2pm today, and the full report will be available online at 5pm.

The Rena on the morning it hit the Astrolabe Reef in 2011.

A presentation will be made by chief commissioner John Marshall QC, supported by chief investigator Captain Tim Burfoot and Rena Investigator Rob Thompson.

The commission's Rena investigation has looked into the circumstances leading up to the grounding, and not of the oil spill response or salvage operation.

It is independent of all other central or local government interests or issues with respect to the Rena.

The Commission's role is to determine the circumstances and causes of accidents and incidents with a view to avoiding similar occurrences in the future and not for the purposes of assigning blame or liability.

An interim report released in March 2012 found human error and bridge culture issues allowed the containership Rena to strike the Astrolabe Reef in clear weather in the early hours of October 5, 2011.

A subsequent interim report found that navigation errors were not picked up and that marks were added to charts after the grounding.

The report sets out the facts and circumstances as established at this point, but does not contain any analysis of the facts or make any findings or recommendations.

The facts are that the Rena's last known position before she struck the reef, was at 1.42am when the ship was around 20 nautical miles east north east of the reef.

A seaman tasked with plotting the ship's GPS position on the chart at 2am failed to do so because the captain and the second mate were leaning over the chart table discussing preparations for their arrival at Tauranga.

The position was instead entered in the log book, and plotted on the chart after the grounding – and at a position further north. The log book was then changed to match the charted position.

The interim report also noted the second mate set up the ship's radar to show if the ship had deviated from its track, but the parallel indexing was switched off at 1.58am to remove clutter from the screen. At 1:50 the ship was heading directly towards the reef.

Investigator in charge of the Rena inquiry, Robert Thompson, says the bridge issues and ‘bridge culture' issues will be part of the final report.

He also says the investigation found no evidence to support allegations that the captain was involved in birthday celebrations during the voyage.

The Rena was steered by autopilot for most of the voyage from Napier, including from midnight until the time of the grounding.

The Commission's interim report on the Rena grounding is available here.