Specialist divers are in their final preparation stages before they embark on removing the 700 tonne house of the sunken Rena.

Resolve Salvage and Fire dive team have been undertaking preparation for the cut and lift of the accommodation block expected to start in the next few days.

Resolve boats over the Astrolabe Reef.

The containership bound for Tauranga struck Astrolabe Reef on October 5, 2011, and later broke up with the stern section sliding down the reef into deeper water.

The decision to remove the four-storey house was made in response to community consultation and concerns raised about the possibility the accommodation block would degrade or collapse in the future, and release debris that could wash up on the shoreline.

It's taken more than 75 days of diving at significant depths to prepare the 700 tonne house structure to be cut and lifted. Divers have now just three more days of work to feed the last two of eight lifting chains through the upper house before the cutting chain can be set up.

Preparations have resulted in two separate incidents while diving at depths up to 46 metres. Both divers received treatment by an Auckland based hyperbaric based specialist doctor before being treated overnight in Tauranga Hospital, but sustained no serious injury.

The cut and lift operation itself requires two separate near-perfect 72-hour weather windows to succeed safely.

In context, in 2013 there have been more than 200 days where salvors have been unable to operate on the wreck due to weather and sea conditions.

The cut and lift operation will see the deployment of the RMG 280 and the RMG 500 crane barge out to the reef.

A specialised chain cutting methodology will be used due to the stern section's 55 degree list in order to cut the house into two approximately 350-tonne sections.

Once cut, these will be loaded onto a third barge, the RMG 1000, cut into smaller pieces and then taken back to the Port of Tauranga for recycling.