Stuart Edmonston, Loss Prevention Director at UK P&I Club, discusses an incident which occurred when a small tanker attempted to overtake a bulk carrier and advises on the lessons that can be learnt from this:
“In conditions of good weather and visibility, a small tanker and an overtaking capesize bulk carrier were proceeding in a north easterly direction towards a traffic separation scheme. The tanker was steering a course of 034o(T) at a speed of 10.5 knots and the overtaking bulk carrier was steering 036o(T) at a speed of 12.5 knots. The tanker’s OOW went onto both bridge wings during this period, but did not notice the bulker approaching from astern as his attention was directed forward of the beam.
“As the vessels came into close proximity, the effect of hydrodynamic interaction pushed the tanker’s stern to starboard, resulting in the bulker colliding with the port side of the tanker. The collision caused serious damage to the tanker’s hull structure and consequential flooding.
“The collision was principally caused by the failure of the overtaking bulker to comply with her obligation under Rule 13 of the COLREGS to keep clear of the vessel being overtaken. A proper lookout was not being maintained on either vessel. In the case of the tanker, the OOW failed to keep a proper lookout by all available means over a full 360o arc of the horizon and as a consequence, did not take the appropriate avoiding action required of a stand-on vessel under Rule 17 of the COLREGS.”
Lessons Learnt: 
· A proper lookout must be maintained by all available means, including sight, hearing and radar over a full 360o arc of the horizon
· Where there is risk of collision, the give-way vessel shall, so far as possible, take early and substantial avoiding action and monitor its effectiveness closely
· Under Rule 13 of the COLREGS, it is the responsibility of the overtaking vessel to keep out of the way of the vessel being overtaken
· The vessel being overtaken, as stand-on vessel, is required by Rule 17 to keep her course and speed
· The stand-on vessel may however take action to avoid collision as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action
· When, from any cause, the stand-on vessel finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision
Source: UK P&I Club