94040 VTS False Radar Info

 

Limitations of Accuracy of VTS Ship Identification
- Wandelaar.
- Report No. 94040.

Own vessel eastbound in West Hinder TSS having reported to Traffic Centre Wandelaar (TCW), in daylight and good visibility with moderate traffic density. Requested ship identification from TCW of a distant vessel fine to starboard and end on, one of several outward bound vessels, quoting approximate range and bearing of same from navigational mark. I received a confident response from the VTS operator.
My intention was to propose and agree an alteration to port at a safe distance, taking me north of the Akkaert Bank and thus clear of the congested pilot ground. At four miles range I called the ship by name, identifying own vessel's position relative to navigation mark and endeavouring to confirm other vessel's position.
After a rather confusing exchange, aggravated by limited command of English in other ship, it became obvious that the ship being addressed was not the vessel named earlier by the VTS and in fact that vessel was shortly afterwards observed passing clear of us to port.
I later visited the VTS control tower and discussed the incident with the duty pilot who, without excluding the possibility of simple human error, considered the following explanation to be a possibility:

In common with many VTS radar systems, targets acquired are given a target name label. With several labelled ships in close proximity it sometimes happens that the labels jump from target to target rather in the manner of shipboard ARPA vectors under similar circumstances.

On this occasion the care taken to confirm identity and the relative positions of the traffic in the vicinity, ensured that no problems arose. However, the potential for a major misunderstanding and consequent close quarter situation might otherwise have existed, particularly in thick weather.

The incident confirms the importance of establishing positive mutual identification whenever making VHF contact with another vessel, especially if initiating a manoeuvre – even when prior ship identification has been made by a VTS or Port Radar operator.