My Speculation on USS Fitzgerald – ACX Crystal Collision

USS Fitzgerald



ACX Crystal



Crystal Vessel Track

The Crystal’s track from an Automatic Identification System (AIS).



This plot appears to show the Crystal making a 90° port turn into the collision at 17:29 UTC (02:29 LT)

A finer scale time lapse animation of the ACX Crystal’s track is available on YouTube.   From this we get this tract, I have added approximate course of Fitzgerald and event times from the AIS time tags.  There is a discrepancy in the times, if I read the Marine Traffic time stamps correctly, and it is UTC, there is a one hour difference, that need to be resolved.  The T-4 time tag is approximate position of Crystal at 17:30 according to Marine traffic’s time stamp.



If the AIS data is correct, and the collision occurred at T-3,  the ACX Crystal was on a parallel reciprocal course from the Fitzgerald when it did a 180° turn to port at T-1 (17:45 ?),  Then at T-2 (18:28 ? ) it did a 90° turn to port before colliding with the Fitzgerald at T-3 (18:35 ?).  The reported time were:

T-1   17:45 UTC ?


T-2   18:28 UTC ?

My T-3 is about the time of the collision, based on the vessel track, not the reported time of the collision.

Note: I find it strange that the mainstream news media hasn’t purchased a copy of the Marine Traffic data and presented an analysis similar to this.

T-3   18:35 UTC ?

From AIS reporting it appears the normal cruise speed of the ACX Crystal is 20 kts.  I will assume, based on the “30 knot Navy” that the Fitzgerald was like doing 30 knots or more, overtaking the Crystal.

Alternate Scenario

If the collision occurred at T-4 then the Fitzgerald track would have had to been 90° to the Crystal track, heading northerly.  The Crystal’s post collision track would have been loitering in the area.


The erratic track of the ACX Crystal prior to the collision (T-3 or T-4)  certainly raise the possibility of some form of mechanical failure.

Likewise the 90° turn to port just prior to the collision (T-3)  raises the possibility of an intentional ramming.

I will leave it to those more knowledgeable to comment on the lane separation distance, T-3 scenario.

June 20 Update

Another AIS video, annotated with vessel speed;

Just to add a little more fog to the narrative, the time of the collision is now in question, according to Daily Mail article.




4 thoughts on “My Speculation on USS Fitzgerald – ACX Crystal Collision”

  1. I feel terribly sorry for the 7 sailors who were apparently asleep and died in their bunks by drowning ( the worse form of death a sailor should experience) when the incident happened. Who was on watch? Who was manning the radar? Add to this… the another incident of a sailor being missing (lost) on his own ship for 7 days…the Navy is looking pretty unorganized. …not to mention the task force that was supposedly headed to North Korea when it was really steaming to Australia instead.


  2. It would be normal for the President of the United States to offer condolence to the families of the dead. How has he missed this military news story?


    1. Trump: “Thoughts and prayers with the sailors of USS Fitzgerald and their families. Thank you to our Japanese allies for their assistance.” Has he called the families in the one day since the identities were release? No reports. I would also question “normal” in the case of accident, certainly it hasn’t been normal in the case of KIA’s. The norm seems to be a “personal” letter.


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