Rig grounded on Lewis beach towed away by two tugs
Transocean Winner, the rig that grounded on a west Lewis beach two weeks ago, has begun to be towed round the island by two tugs.
The 17,000-tonne structure was refloated on a high tide at 22:04 on Monday.
The tugs Union Bear and Union Princess are towing the rig to the east side of Lewis.
The journey to Broad Bay covers about 54 miles (87km) and was expected to take more than a day to complete.
Hugh Shaw, the Secretary of State's Representative for Maritime Salvage and Intervention, who is overseeing the salvage operation, said the passage to Broad Bay was slower than anticipated.
He told BBC Radio's Good Morning Scotland programme it could be the early hours of Wednesday morning before the rig reached the bay, where the structure would be secured to eight anchors.
Mr Shaw said the phase of the salvage operation to move the rig from where it ran aground on a beach at Dalmore had been a "success". He said a "fantastic job" was done by personnel on board the tugs and Transocean Winner.
The beach at Dalmore, near Carloway, remains off limits to the public until checks have been made for debris and other pollution.
Mr Shaw said there were no pollution concerns at this stage and a sheen of oil detected on the surface of the sea in the initial stages of the tow had been found to amount to a litre of oil.
Tonnes of diesel oil have been removed from the rig's fuel tanks. However, thousands of gallons of the fuel was lost from two tanks during the grounding of the rig.
Mr Shaw said monitoring for pollution was ongoing, adding: "An aircraft from the Maritime and Coastguard Agency will overfly the bay where it was last night and then overfly the tow itself."
Transocean Winner could remain in Broad Bay until the middle of September while divers check for damage, and the rig's owners, Transocean, make a decision on what to do with the rig.
BBC Scotland's Huw Williams reports on rig's refloat at Dalmore beach
At first the movement was too gentle to be visible from the shore, but then came confirmation from the salvage tugs it was underway.
There was applause from the 75 or so local people and visitors who had gathered to watch the Transocean Winner go.
The semi submersible rig had been aground on rocks at Dalmore's idyllic beach on the west coast of the island of Lewis for the past two weeks.
It will take 20 hours or so to get it round to a bay where it can be securely anchored and its condition properly assessed.
So this is the end of this part of the story, but there are questions still to be answered about how and why it went aground in the first place.
It was being towed from Norway to Malta, from where it was to be later moved to a yard in Turkey to be broken up.
Mr Shaw said options open to Transocean included resuming that tow or, if the rig was found to be too badly damaged, loading it on to a semi submersible ship and moving it that way.
He acknowledged that there were yards on the Western Isles and Scotland's west coast that could potentially handle the scrapping of the rig, but he said it was for Transocean to make a decision on where the rig ended up.