SCIENCE AND THE SEA 



The opinions and conclusions expressed in the 

 analyses are those of the author and are intended 

 to place maximum emphasis on the lessons to be 

 learned. Serious consideration of these lessons by 

 all mariners involved in the navigation of ships 

 could lead to a significant reduction in the number 

 of collisions in the future. 



CASE 1 



The principals in this case v/ere tw^o American 

 dry-cargo vessels that collided in the Yellow Sea 

 off the west coast of Korea during a period of 

 restricted visibility. The weather at the time 

 consisted of a southwesterly wind, force 3-4, with 

 light rain, mist, and patchy fog. The range of 

 visibility was estimated to be less than a mile. A 

 slight to moderate sea was running with very 

 little swell. Both vessels were equipped with radar 

 which was reported to have been in good operation 

 at the time of the casualty. 



NARRATIVE 



SHIP A 



Ship A was enroute from Inchon, Korea, to 

 Pusan, Korea, with general cargo. After departure 

 the master maintained the conn until the ship was 

 clear of the island group just south of Inchon. 



Shortly after midnight the ship entered the 

 relatively open waters of the Yellow Sea, where- 

 upon the master relinquished the conn to the mate 

 of the watch and went below. 



The vessel proceeded southward at 16 knots 

 on a course of 186°T. Due to the limited visibility 

 and the unexpected presence of local fishing craft, 

 the watch officer frequently scanned the radar 

 screen which was set on the 8-mile scale. At 0324 

 he thus observed a large target. Ship B, which he 

 estimated to be dead ahead (186°T) at a distance of 

 approximately 8 miles. This fix as well as the 

 subsequent radar fixes of Ship Bhy Ship A proved 

 to be erroneous by 11°E to 15°E in bearing and 

 consistently IV4 miles in excess of that which can 

 be substantiated by reconstruction. 



One minute later, obviously unaware of his 

 radar's error, the watch officer observed that the 

 target bore 184°T, range 7.5 miles. Believing this 

 contact to be a large, fast ship because of its pip 

 size and high closing speed, the watch officer 

 changed course to 209 °T. At 0328 he calculated 

 that the target bore 183°T, 5.5 miles distant. 

 Around 0330, again noting the speed at which the 

 target was closing and that the bearing had not 

 changed appreciably, the watch officer changed 

 course to 229 °T. At this time the two ships were 



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