Regulated under SOLAS Chapter V (Regulation 12) and IMO Resolution A.1158(32)
What is a VTS?
A Vessel Traffic Service is a service implemented by a Government with the capability to interact with vessel traffic and respond to developing situations within a VTS area to improve safety and efficiency of navigation, contribute to the safety of life at sea and support the protection of the environment.
Under IMO Resolution A.1158(32), the establishment of a VTS depends on national law and is assessed through risk assessment, considering the volume of traffic, the degree of risk and geographical and environmental conditions. The Government appoints a Competent Authority, which authorises a VTS Provider to operate the service within a delineated VTS area. The master always retains ultimate responsibility for safe navigation.
VTS operators work from a purpose-built VTS Centre equipped with integrated radar, AIS, VHF radio, CCTV and meteorological displays. They maintain a continuous operational picture of all vessels in the VTS area and provide services ranging from information broadcasts to advice, warnings and instructions.
Typical VTS areas
A.1158(32) no longer classifies VTS as "port" or "coastal": each service operates within a VTS area — a delineated, formally declared area. VTS may also extend beyond territorial seas on a voluntary-participation basis, and neighbouring Governments may establish coordinated VTS.
Port VTS
Port area and access channels; high density, complex manoeuvres
Coastal VTS
Open coastal stretches and straits; traffic separation schemes
Inland VTS
Rivers and canals; mixed commercial and recreational traffic
Combined
Hybrid coverage spanning port and adjacent coastal waters
Three VTS Functions
To achieve their purpose, VTS provide information or issue advice, warnings and instructions, as deemed necessary.
VTS sensor infrastructure
Technologies deployed in a fully equipped VTS Centre
The VTS operational picture
The Recognised Maritime Picture (RMP) is the fused display of all sensor inputs - radar tracks, AIS targets, CCTV feeds and meteorological overlays - presented to the operator on an Electronic Chart Display (ECD).
Modern VTS workstations correlate AIS and radar targets automatically, flagging discrepancies (e.g. a vessel without AIS, or a position mismatch) as alerts. The operator can annotate targets, assign waypoints and log incidents directly on the chart interface.
Radar / AIS fusion
Automatic correlation of radar and AIS returns into a single track
CPA / TCPA alerts
Closest Point of Approach and Time to CPA alarms for collision risk
Voyage plan overlay
Vessel-submitted voyage plans displayed over ENC chart
Incident log
Time-stamped record of all VTS actions and communications
VTS Personnel Competence
VTS personnel are considered competent only when they have completed generic VTS training approved by the Competent Authority, completed on-the-job training at their VTS, undergo periodic assessment and revalidation, and hold appropriate certification.
VTS Operator
IALA C0103-1
VTS Supervisor
IALA C0103-2