Full survey work and assessments expected to provide detailed 3D imaging of the sunken stern section of the Rena are expected to be carried out and completed this month.

Last month divers preparing for the second cut and lift operation on the Rena' accommodation block observed the position of the vessel's stern section on the reef has changed.

Debris from the Rena on the bottom of the reef.

As a result the stern was previously surveyed listing at 55 degrees, and that list to starboard has now increased – believed to have occurred sometime after Cyclone Lusi hit the region during March 15-16.

Following the discovery divers spent the next two days conducting a visual survey to perform an initial check of changes in the ship's position. The divers are reported to have not seen any damage to the reef itself from the movement.

The containership Rena struck the Astrolabe Reef, about 25km off the coast of Tauranga, on October 5, 2011. The ship leaked more than 350 tonnes of heavy fuel oil into the environment and broke up, spilling containers and cargo into the ocean, washing up on beaches across the Bay of Plenty

Captain John Owen of The Swedish Club, the Rena owner's insurer, says a full wreck survey will be conducted on the Rena following removal of the first half the accommodation block. A further update is expected at the end of April.

The first 300 tonne section of the accommodation block was towed into Tauranga Harbour on March 13.

The ADUS (underwater sonar) survey will secure a 3D computer model of the ship's position, and confirm the extent of the movement and any effect this may have had on the structure sometime this month. The remaining bow section will also be surveyed.

John says the survey will help clarify what impact this movement might have on future salvage operations and any updates necessary to the assessment information of the resource consent application.

The Rena's owners, Daina Shipping Company, and insurers are currently putting together a resource consent application to apply to the Bay of Plenty Regional Council to leave the wreck on the reef once the accommodation block has been removed.

They believe further salvage operations removing sections of the wreck could disrupt the contaminants dispersing them throughout the marine life and put environmental recovery of the surrounding area back between five to 10 years.

'We're sharing this information now to that the community knows what is happening on site. And to advise that there will be further delays to our work programme,” says John.

'A further update will be provided once the survey has been completed and the information thoroughly assessed, which should be by the end of April.”