A salvage team has managed to get back on board the stricken oil rig Transocean Winner in order to carry out a full assessment of damage.
Eight experts scaled the structure using ropes, after bad weather hampered previous attempts to board the rig.
Since the rig ran aground off Lewis on Monday, salvors have only been able to make a short assessment of its condition.
More than 12,000 gallons of diesel oil have been lost from its tanks.
On Sunday, the Maritime and Coastguard Agency (MCA) said rope technicians had created “a safe alternative access” to the rig.
The salvors intend to make the rig habitable so they can remain on it overnight.
Work is also being done to provide a supply line so the team can get equipment and supplies on board.
In a statement, MCA said the salvors would look at the rig’s diesel oil tanks to examine how fuel might be transferred to other unbreached tanks before any operation to refloat the rig begins.
Survey work is also being carried out to identify the safest route to move the rig when the time comes.
Another aircraft is being brought in to help with the work.
Hugh Shaw, the Secretary of State’s representative for Maritime Salvage and Intervention, said: “Once the assessment is under way, we’ll have a much better idea of what we are dealing with, which will mean a more detailed salvage plan can be drawn up and put into place.
“We’ve made a commitment to keeping people informed locally and we intend to keep to that – once I’m happy that the plan is ready, we will be sharing it with community leaders and the community as a whole.”
A 300m exclusion zone remains in place around the rig. It covers both sea and air, which means no drones will be permitted in the area.
The Transocean Winner was being towed from Norway to Malta from where it was to be moved to a yard in Turkey to be broken up.
A tow line between the rig and a tug broke during stormy weather and the structure ran aground at Dalmore at about 07:30 BST on Monday.
Related conference: http://www.wplgroup.com/aci/event/maritime-salvage-casualty-response/