202071 Contact with buoy

A tanker was approaching a crowded anchorage area where a ship-to-ship transfer (STS) was to take place. Visibility and weather conditions were good and the bridge team was fully mobilised with the Master, two officers, a helmsman and a lookout on duty. As the vessel approached the pick-up position of the Mooring Master, a small police boat was moving somewhat erratically ahead. There were other vessels anchored to starboard, so the tanker’s bridge team altered course to port and slowed to about 3 knots.
Speed was further reduced and soon the STS Mooring Master arrived along with two tugs. The tanker, now almost stopped, was affected by the NW current. Shortly after the STS Mooring Master had boarded, the tanker’s port side lightly made contact with an anchorage buoy. The buoy slid aft along the hull and its chain became entangled with the vessel’s propeller and rudder. The mooring and STS operation was aborted and the tanker anchored with tug assistance. The chain was cleared with the help of divers. Some minor damage to the propeller was recorded.

Lessons learned

• Even in perfect weather conditions and full daylight, a bridge team can lose situational awareness. It is possible that the boarding of the STS Mooring Master combined with the erratic movements of the police boat and other congestion preoccupied the bridge team and caused the tanker’s movement towards the buoy to go unnoticed until it was too late.
• One bridge team member should be tasked with overall situational awareness at all times, but especially when in congested waters and under close manoeuvring.