Misuse of ARPA Causes Close Call

The UK Marine Accident Investigation Branch (MAIB) issued the report of its investigation into the close-quarters situation that occurred between a cruise ship and a car carrier in the Dover Strait Traffic Separation Scheme (TSS) on 15 May 2008.  The car carrier, along with a number of other vessels, was proceeding in the southwest lane of the TSS.  The cruise ship intended to cross the southwest lane en route from Le Havre to Harwich.  The master and the navigation officer on the cruise ship conducted several trial maneuvers utilizing the ARPA on the radar prior to executing the actual maneuver.  Unfortunately, due to their unfamiliarity with the trial maneuver feature, they obtained a result that made the maneuver appear safer than was actually the case.  Further, the bridge team on the cruise ship was slow to appreciate the risk of collision.  Report No. 20/2008 (11/19/08).

(Source: Holland & Knight)