Divers will today attempt to block pipes to prevent any diesel spilling from a boat which has sunk near Bluff.
Three fishermen were rescued early this morning after their boat sunk following a "navigation error" returning into the Bluff harbour.
Coastguard president Andy Johnstone said the vessel, the Ayson, had been filled with fish when it suffered a mechanical fault and had to return to Bluff.
Two of the three crew were sleeping while the third steered the Ayson back into port.
The boat sunk just metres from the rocks at Stirling Point, in water about 10 metres deep, he said.
It was a common path for boats to use to return Bluff, he said.
"It was just an error in navigation judgement."
The boat went down quickly, but they managed to get on the life raft and set off the beacon without getting their feet wet, he said.
The rescue crew were back to work and bed within the hour, he said.
The Environment Southland Marine Oil Spill Response Team estimated 3,000-5,000 litres of diesel was onboard the vessel.
Regional-on-scene commander Dallas Bradley said currently only a small diesel spill had been caused, probably by fuel escaping the fuel tank breather pipes. There were no indications diesel had entered Bluff Harbour.
He said the owners planned to dive on the vessel today to block the breather pipes and assess damage.
Any salvage of the vessel could take some days, said Bradley.
Environment Southland wouldl continue to monitor any spillage and its path.
- The Press
Which memorial design do you like most?Related story: Christchurch earthquake memorial designs unveiled