Remote operated vehicles will be cruising the Western Bay of Plenty sea floor next week in search of submerged containers from the Rena wreck.

The planned search comes after container recovery team Braemar Howells' completion of a comprehensive sonar sweep of about 800sqkm of the seabed this week, which identified 50 objects most likely to be containers.

Containers released from the stern section after the wreck deteriorated in bad weather. Photo: LOC.

This area surrounds the Rena wreck on Astrolabe Reef and includes areas close to shore, Port of Tauranga shipping lanes, and also encompasses the seabed near Matakana and Motiti Islands.

Braemar operations manager Neil Lloyd says all targets identified in the sonar operations have been ranked according to the likelihood that they are containers.

About 50 of the most likely container looking targets will now be investigated in stage two of operations.

Neil says some of the targets may also be rocks.

Weather permitting an ROV will be lowered from a ship over each likely site. The onboard camera will allow operators aboard to see what the targets are and use a manipulator arm on the vehicle means to attach containers for later removal.

Neil says the targets are at depths of 30 to 80metres and the containers and container remnants in less than 30m of water have already been retrieved.

Stage Three of operations will involve the recovery of newly identified containers. A timeline for this has yet to be finalised.

Braemar Howells is working on the recovery of distressed cargo from the Rena, which grounded on the Astrolabe Reef about 25km off the coast of Tauranga on October 5, 2011.

At last count 772 containers have been salvaged from the Rena while more than 500 remain on board the wreck remains or on the sea floor.

Svitzer Salvage is responsible for salvaging the ship itself.