When the bad weather lifts an attempt will be made to survey the cargo ship which sank in the Pentland Firth two weeks ago to try to explain its demise.

Marine Accident Investigation Branch (MAIB) inspectors want to know why the vessel foundered so rapidly; why none of the crew survived; and why it took so long for the alarm to be raised.

The Cypriot-registered Cemfjord is lying on the seabed 15 miles from Wick with all eight crew members lost , presumed dead.

MAIB inspectors are embarking on the Northern Lighthouse Board vessel Pharos this weekend to take advantage of a forecast lull in the weather on Sunday and Monday to conduct a Remotely Operated Underwater Vehicle (ROV) survey of the wreck of the cement carrier.

The ROV will be operated by salvage experts from the MoD's Salvage and Marine Operations Project Team.

The Cemfjord capsized at around 1300 on January 2 while attempting to sail through the Pentland Firth. The upturned hull was discovered the following day by the Shetland to Aberdeen ferry, and the hull was tracked until it sank some 20 miles east of the Firth in over 200ft of water.

The MAIB said "The wreck lies in an area of strong currents that are likely to hamper ROV operations and limit underwater visibility. The need to use an ROV capable of operating in such conditions means that it is too large to enter the wreck."