Underfire
Your explanation of a possible search pattern is interesting. However, when the PMS Burullus was visible on AIS there were several puzzling things whcih do not seem to fit the scenario you have described. She was sailing at variously 0.4 kts and 0.3 kts all the time. She did not seem to be slowing to turn, it was just very, very slow all the time - and there were many observation points along its route where data was available, so this was not a sampling problem. AIS reports show many items of data, including the ships actual heading as well as its course over the ground. The heading showed that at all times when zig zagging the vessel had its head pointing NE, no matter which way it moved. When moving to its search area the heading was different, suggesting this was not just "stuck" data in the AIS stream, but was the actual heading as it moved. I guess that was holding the ship "head into the prevailing wind", but I have not checked the weather. Lastly the scale of the pattern it was sweeping was very "tight", with only 1Km - roughly 0.5 nautical mile - along each "long" leg and with 200 odd metre gaps between passes.
None of these seem to me to fit with a towed anything. Maybe it was a "dangled" something, or perhaps as has been suggested it was tracking a self powered ROV with or without an umbilical.
Any thoughts about what it was using?
Just noticed French Warship 9014 is back in the area and is "moving" in a way that suggests it is looking for something. Moving at 10 or 11 knots most of the time. There is a period where there were no position reports when it moved only a few Km in 4 hours.
And there is a survey ship - the Hugin Explorer just to the NE of the supposed site. It arrived in the area from Cyprus at 11 knots and now seems to be just drifting.
Last edited by AT1; 29th May 2016 at 08:41.
Reason: Update