The salvage team assigned to the Transocean Winner is finalising plans for refloating the stricken oil rig later today.
The semi-submersible has been marooned off the west coast of the Isle of Lewis since it broke a towline during a storm two weeks ago.
Recovery experts intend to refloat the vessel at high tide tonight before towing it to Broad Bay on the east coast of Lewis.
The Maritime and Coastguard Agency said Smit Salvage had agreed a towage plan with Hugh Shaw, who is in charge of the operation.
There will be a 3,330ft exclusion zone around the Transocean Winner for the duration of its passage from Dalmore Bay to Broad Bay.
The Western Isles Emergency Planning Co-ordinating Group is discussing plans to enable people to visit and view the refloat tonight.
Mr Shaw, the secretary of state’s representative for maritime salvage and intervention, said: “We have commenced the final phase of this part of the operation.
“The two tugs who will be towing are already connected and standing by off Dalmore Beach. The refloat is scheduled to take place later tonight.
“We’re aware of how much interest there has been in this rig and completely understand that. And we know that people will want to watch it.
“All we ask is that everyone follows the guidance that is being put out by the Western Isles Emergency Planning Co-ordinating Group so that they can watch it safely.”
A verification aircraft will be sent to monitor for any potential pollution, the MCA added.
“A survey yesterday picked up a sheen which turned out to be 200ml and was quickly broken up using boats by Briggs Environmental,” the agency said.