Marine services are port-related activities conducted to ensure the safe and expeditious flow of vessel traffic in port approaches and harbors and a safe stay at berth when moored or at anchor. Safe means that port conditions ensure that vessels using the port, the port environment, and the marine environment are protected from danger. Expeditious means that vessels are not unduly delayed and that the vessels port transit times as a part of the total turnaround time in the port are kept to a minimum. Although ports may define marine services differently and may have different methods of providing them, in this section the term is used to refer generally to services having a nautical bearing, be it maritime safety, vessel traffic efficiency, or marine environment protection.
Other services (for example, fire fighting, immigration and customs services, security, and port state control) may also affect port efficiency and safety. While important to the overall operation of a port, these other services are not dealt with in this section. The specific marine services rendered by a port authority depend largely on the scope of the port's marine responsibilities and jurisdiction. The scope of the ports' marine jurisdictions does not follow a general rule, and there exists no international legislation or standard practice that defines the responsibilities of port authorities. Usually, marine services rendered by a port authority are geographically delimited by the area directly under control of the authority, which may encompass only the waterfront of riparian berths (the port's domain). However, there are countries where the port authority is also responsible for managing lighthouse services outside its immediate area of control. This extended area may cover harbor waters and approaches as far as the open sea.
The control of dangerous goods for maritime cargoes is usually performed by a specialized branch of the port authority. The same goes for the handling of dangerous goods in port terminals. Oversight and regulation of land transport of dangerous goods is normally a responsibility of the central government.