Office of Coast Survey
National Oceanic and Atmospheric Administration
U.S. Department of Commerce

Precision Navigation

What is Precision Navigation?

Precision navigation, in marine transportation terms, is the ability of a vessel to safely and efficiently navigate and operate in close proximity to the seafloor, narrow channels, or other hazards. For large vessels entering a port— when space is tight and time is critical—mariners anticipate ocean and weather conditions by using observations, forecasts, and underlying foundational data in addition to nautical charts. With this in mind, NOAA is defining a process of collecting and integrating data to create more accurate navigational products and tools that support the mariner’s operational decision-making process.

Port of Long Beach Pilot Project

In the Port of Long Beach, ultra-large crude carriers were vulnerable to potential groundings when waves arrived in long period swells. As a precaution, the port reduced the maximum allowable ship draft to 65’, even though the channel is dredged to 76’. Coast Survey collaborated with private industry and within NOAA to create a precision navigation model for the Port of Long Beach. The observations, forecasts, and foundational data in the model include:

  • Nearshore Wave Prediction System (NWPS) for forecasts of wave and swell conditions
  • Water levels for predictions and real-time values available from PORTS®
  • Wave buoys for real-time values and 3-hour nowcast short term predictions
  • Lidar for shoreline updates to nautical charts
  • Hydrographic surveys and high resolution bathymetric inland ENC overlays for increased accuracy and resolution over traditional charting products

Due to the success of the model, the U.S. Coast Guard Captain of the Port removed the 65’ draft restriction. The long-term goal is to achieve 69’ draft transits safely, at which time lightering offshore will no longer be required, improving operational efficiencies, safety, and reduce environmental risk.

Precision Navigation success in the Port of Long Beach

Precision navigation in the Port of Long Beach will save vessels an estimated $10 million per year in lightering costs. Additionally, for every extra foot of draft allowed by the port, tank vessels can load $2 million of extra product.

Revised: 11/29/2018