More than half of the fuel remaining on the stricken cargo ship on the coast near Colwyn Bay has now been removed. 14,000 litres of oil from the MV Carrier has been pumped out, with around 10,000 estimated to be left.
The speed of the process is limited by the fact that work can only continue in four-hour blocks, two hours either side of low-tide, but not in the dark. A 100-metre exclusion zone has been put in place for other boats off the coast, while a speed limit remains in place on the A55.
The Maritime and Coastguard Agency say their priority is to remove the oil from the stricken tanker that is grounded on the rocks near Llanddulas in north Wales.
Coastguards say they believe the fuel tanks aboard the MV Carrier to be intact, and that any fuel leak is likely to have been a small amount from the engine.
Salvage experts are still working on plans for the recovery of the ship, though at the moment there is no timescale for that to take place.
The Marine and Coastguard Agency said that the 82-metre long ship has been holed in three places on the starboard side.
ITV Wales reporter Ian Lang says that one option being considered is to patch up the tanker and float her off.
People nearby have reported a strong smell of fumes since the vessel ran aground on Tuesday night.
The vessel is loaded with stone, but there is no way to off load that at the jetty.
Environmentalists are also worried about the affect any more oil leaked from the tanker could have on wildlife in the area. The RSPB says the area is home to internationally important numbers of birds.