A 350 tonne block of the sunken accommodation section of the Rena wreck has been cut off and dragged to Motiti Island where salvors are attempting to lift it.

Resolve Salvage and Fire workers yesterday managed to cut the section lying beneath the water at Astrolabe Reef and drag it about 11km to the eastern side of Motiti Island.

But salvage spokesperson Hugo Shanahan says the first attempt to lift the section from the 35 metre deep water onto the RMG 500 barge to bring it back to shore was hindered by a twist in the shackle used to lift.

'Divers are in the water this morning attempting to correct that shackle.

'There is a twist in the shackle in the hoist chain, so divers need to get back down there and right the shackle, and then once that's fixed they can have another attempt to lift it back onto the barge.”

The twist in the shackle was discovered about midnight on Tuesday, and Hugo says salvors and divers have been working to right it since first thing today.

'The cutting went really well, the lifting and the conditions on site are proving a problem.”

The 236 metre ship hit the Astrolabe Reef about 25km off the coast of Tauranga on October 5, 2011. It spilled more than 350 tonnes of heavy fuel oil into the ocean and subsequently broke in two in early 2012. The forward section of the ship has now been cut to 1 metre below the waterline, while the aft section remains wedged hard on the reef.

Salvors are now working to cut sections of the stern section, which includes the accommodation block used to house staff working on the ship.

On Monday underwater divers began cutting the bridge and decks of the house section, which was then lifted to the surface.

Hugo says any small thing to go wrong can slow things down for salvors who are working in difficult conditions that are dependent on the weather.

'It's incredible how one little thing can cause such a long delay. This shackle means a lot of work for the divers today.”

The westerly wind is knocking out the swell today, so Hugo says salvors will have a good chance of lifting the section late today.

Once the section is lifted it will be brought back to the Port of Tauranga.