Navigational near-miss in restricted visibility

A member has reported a near miss incident in which an offshore wind farm crew transfer vessel (CTV) avoided another vessel in its path during a period of restricted visibility. The incident occurred when the vessel was on passage along the designated wind farm traffic route. It entered a fog bank which resulted in visibility being reduced to less than 100m. Upon entering the fog bank, the Master reduced to minimum steerage way, posted a lookout in the wheelhouse and commenced making sound signals as required by International Maritime Organization (IMO) collision regulations. In addition to this, a second crew member prepared to mount a watch on the foredeck, and the intercom external speaker was activated to monitor for sound signals of other vessels.

Another vessel ahead was sighted at less than 100m away. It was at anchor in the wind farm traffic route. The Master immediately stopped the CTV and then proceeded slowly around the anchored vessel, which was not making any sound signals nor was an Automatic Identification System (AIS) signal noted. Although the CTV had radar operating on the 2 mile range the anchored vessel was not detected. This incident was reported to the UK Marine Accident Investigation Branch (MAIB) and the client.

Our member took the following recommendations:

• Amend the generic risk assessment for navigation, along with the company procedures for small vessel operations, to reflect this incident;
• Ensure Masters are aware of their radar settings, as improperly adjusted rain and sea clutter or gain settings can affect reception;
• Ensure Masters are able to use known objects such a channel buoys to confirm correct calibration.