Traffic separation schemes and other ships’ routeing systems may be combined with a vessel traffic service (VTS), which is defined as a service designed to improve the safety and efficiency of vessel traffic and to protect the environment.
In other words we can understand VTS as:
A vessel traffic service (VTS) is a marine traffic monitoring system established by harbour or port authorities, similar to air traffic control for aircraft. Typical VTS systems use radar, closed-circuit television (CCTV), VHF radiotelephony and automatic identification system( AIS) to keep track of vessel movements and provide navigational safety in a limited geographical area.
