Salvors are "very hopeful'' they will be able to begin pumping oil from Rena's submerged five starboard tank this morning, says Maritime New Zealand.
Twenty salvors on board the stricken vessel Rena are preparing to pump fuel oil from a submerged tank last night, while algal bloom was mistaken for leaked oil in Waihi.
The team is pumping seawater into the submerged starboard wing tank to purge pockets of air that have so far stopped heavy fuel oil from being pumped onto the tanker Awanuia, said Maritime NZ unit manager Kenny Crawford.
Mr Crawford said oil pumping could start once the air pockets had been eliminated.
Divers placed a third hot tap in the side of the tank yesterday to increase the flow of seawater and the tank was being monitored continuously, he said.
An aerial observation flight this morning has reported no apparent change in the vessel's condition.
Salvors have removed over 20 tonnes of clean lubricating oil onto the barge Go Canopus, while also preparing the submerged tank.
The team are continuing to consolidate smaller parcels of engine oil from different compartments to pump them off the Rena.
National On Scene Commander Rob Service said a report of a large amount of oil at Waihi Beach proved to be an algal bloom.
"At this time of year when there are warm temperatures and calm seas, algal blooms are quite common. We expect to receive more reports of `oil' that turn out to be algae, but we will always check them out to make sure,'' he said.
Container barge Sea Tow 60 (ST60) yesterday conducted sea trials preparing to remove containers from the grounded vessel.
The trials included laying anchors to test the mooring systems that will be used when the barge begins removing containers, and were held well away from the Rena so as not to interfere with the oil removal.
Container removal contractor Braemar Howells has two vessels conducting sonar sweeps of the seabed in areas where the water is 30m deep, or less, to check for containers lost overboard in the storm three weeks ago.
Divers were checking items detected by the scans, he said.
Wreckage of three containers has been removed from the Hicks Bay and Waihau area, while another two containers are yet to be removed from Motiti Island.
On shore, oil spill response activities involving NZ Defence Force personnel, oil spill responders, contractors and volunteers will continue.
Oiled wildlife response teams will also be out again today.
About 50 people are working at the oiled wildlife facility, taking care of the 400 birds that have been cleaned, and the three still being treated.
The patients included little blue penguins, who were being hand fed twice a day as well as weighed and checked regularly.
