A loose anchor punched eight holes in one of the pontoons during the night of 6-7 November, allowing water to enter the tanks and causing the unit to list by about 5.8 degrees.
Floatel Superior was then lying on the Njord field in the North Sea, and strong winds and high waves initially created problems for evacuating those on board.
However, helicopters were eventually able to lift everyone but a safety team of 38 people onto other installations in the vicinity.
No injuries were suffered during the actual incident.
The PSA took a very serious view of the event, and quickly decided to initiate an investigation. A report is due to be ready in March, when it will be published on the PSA website. 8