Maritime New Zealand is reporting the bridge section of Rena is almost completely submerged after large seas and strong winds continue to batter the ship.

MNZ says waves of between eight to 10 metres have struck the wreckage on Astrolabe Reef for prolonged periods causing the stern section to roll.

A view of the bridge of Rena taken during an overflight today shows the bridge section almost completely submerged. Photo: MNZ

Svitzer salvors estimate 11 containers, both 20 and 40ft ones, were lost into the sea during the storm on Tuesday, although continuing rough sea conditions are making it difficult to accurately assess the exact number.

Monitoring flights are today surveying the ocean to ascertain how much debris went overboard and what direction it is heading. Indications are the debris trail is heading west toward Matakana Island and Waihi Beach.

The weather forecast at Astrolabe today is for winds of 27 knots (50km/h) and a maximum estimated wave height of 5.5m.

The conditions are forecast to gradually ease, though winds will remain strong and the sea is expected to remain rough for several days.

MNZ National On Scene Commander Rob Service says ongoing rough weather may result in more containers being lost and pockets of oil escaping from the vessel.

'The amount of oil released from the wreck is only a tiny percentage of the oil we saw released in the big spill in October,” says Rob.

'It is unlikely to have a significant impact – however, it is important people are aware there could be some oil on their beaches over the next few days.”

Waikato Regional Council staff today failed to find any sign of oil or debris on Coromandel beaches between Whiritoa and Whitianga.

Monitoring will continue in the coming days with equipment and personnel on standby to aid in the clean up.

Anyone who sees oil is asked to call 0800 645 774, while any container debris should be reported to 0800 333 771.

There have been no reports of any wildlife being affected, but the National Oiled Wildlife Response Team based at Massey University has been alerted and can respond to any reports as needed. The Department of Conservation has also been alerted.