The Maritime and Coastguard Agency (MCA) said final preparations are being made to put a small team of salvors on board the grounded Transcoean Winner off the Isle of Lewis.
The 17,000-tonne rig ran aground yesterday after it broke free from its tug while being towed in rough seas in the early hours of Saturday morning.
The rig, now grounded at Dalmore near Carloway on Lewis, was carrying 280 tonnes of diesel and is now being monitored by a counter-pollution team.
Hugh Shaw, who as Secretary of State’s Representative for Maritime Salvage and Intervention is overseeing the operation, said: “This initial recce will be checking a number of things including fuel tanks.
“Weather permitting, it’s then intended to put a second larger group of salvors on tomorrow to carry out a more detailed inspection.”
Three vessels including the ETV Herakles remain on scene. A temporary exclusion zone of 300 metres has been implemented around the rig.