of the AIS
tracks with a video overlay is interesting. I can understand how this skipper
got into trouble. He was fixated on #1 believing that the ship was/must being going to turn to starboard (as they normally do in this spot and as the ship made sound signals they were in fact going to do), and #2 on the 'proper' port to port passing, and #3 not giving up 'unnecessary' racing
(all times before collision)
4:41 Yacht makes gybe to pass normal ship track port to port. The Ships normally starts turn to starboard shortly after passing the "precautionary area" boundary. The yacht gybe here 'should have been a reasonable move, passing right close behind the ship's stern and giving up minimal racing
distance and speed. A sharper turn to starboard, giving a greater CPA to the ship's expected track, would have been more 'prudent', but the yacht is racing and that would have given up 'unnecessary' distance if the ship had turned as normal and expected.
2:03 Patrol boat guiding ship makes turn to starboard. Sometime just before this the ship made a sound signal that they were going to turn to starboard. But then was blocked from making their turn by a small disabled power boat
. This screws up the yacht's plan.
1:39 Patrol boat identifies risk of collision
and changes course toward yacht.
1:27 Yacht identifies risk of collision
and comes up to starboard to (a) pass port to port) and (b) to avoid "normal" course of ship. The Yacht is still expecting the ship to turn to starboard and still trying to pass port to port. The yacht is already a bit screwed here 1:27 before the actual collision - a turn to port puts right in the 'expected path/turn of the ship and a turn to starboard puts it in the current
path of the ship. Some communication here between the yacht and the ship/patrol boat would have been really really useful, so that the yacht knew which way the ship was going to go. Short of that a drastic maneuver by the yacht was required - blow the chute, start the engine
and turn 100 degrees one way or the other but it would still have been hard to decide which way to turn.
0:18 Yacht comes up as close as possible, losing their spinnaker
trim, still trying to pass port to post and avoid the ship's normal turn. At some point between 1:27 and 0:18 it should have been obvious the ship was just continuing on in a straight path and a crash gybe to port would have been smarter than continuing to try to make a port to port passing.
0:00 Collision. Interesting to note that the AIS gps
antennae must be aft on the ship because the video shows the collision at this time but the AIS plot still shows separation.