In the process of checking positions of debris found in the BEA's Drift Group Report I found that some of the plots were using a position 4NM further north than where it should have been. Another item that I believe has wrongly recorded co-ordinates is the Vertical Stabilizer. There is a "sighted" and a "recovered position which shows that the V/S moved SSW at 1.9 knots between these two positions. I don't believe that was probable, which then leads to which of the two positions is correct?
Having got over those two problems, I plotted a few postions and started to consider the conflict that happened on the northern edge of the 40NM radius circle on 5 and 6 June 2009. It then dawned on me that the Singaporean registered tanker "Ursula" [correct spelling] 9VFJ6 passed through this area, and the chance of debris being sighted would be increased considerably if there was a local eddy and a lot of "stuff" was circulating in a relatively small area. During daylight hours there would only be the Mate on watch on the bridge, and basically just one pair of eyes keeping a casual lookout, but at the time was probably keeping a better lookout than normal following a Radio Nav Warning to shipping regarding the missing aircraft. Then having sighted a body(?) noted its position and then did something about reporting it to RCC, with the ship continuing on its passage without any deviation.
So still considering the SSW drift of the V/S, it became apparent that a localised eddy could help explain the conflicts in timings in this small area, and hence a new graphic which uses some data from a buoy that passed through the area a few days later to show another possibility. Though not shown, because it doesn't really matter, is the starting point which is close to the Pollution Spot. Buoy 246 had a daily drift of about 19NM when it moved NNE after passing just to the south of the LKP, and I have used that sort of drift rate on that part of the track. Everything then slows down when the southern edge of the Counter Current pushing to the west near TASIL causes an abrupt direction change to the SW leading into the clockwise eddy and slowly picks up as the current finishes up heading north to 3Z and 9Z etc..
Note:: The timings and positions don't always match, but then that is to be expected after 6 days.