French sub seals holes on sunken oil tanker Prestige
Strong winds were also pushing a huge slick from the submerged wreck far enough from land to give exhausted fishermen a breather.
But Deputy Prime Minister Mariano Rajoy said the submarine Nautile has detected new cracks in the vessel on the Atlantic seabed which he called small but declined to describe in detail.
The large slick that had Galicia on alert this weekend is actually a concentration of dozens of patches of fuel oil up to five meters (16 feet) long, Rajoy said. Strong winds blowing north have pushed it to the northwest tip of Galicia, 40 nautical miles from land, he said.
Some 8,000 people were working to clean contaminated beaches in Galicia but at least for a day there was no major new threat.
Rajoy said the first crack the Nautile sealed last week appears to be holding. The government initially said the submarine had found 14 cracks or holes through which oil was leaking.