NOAA
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.

Why is Precision Navigation Needed?

Ports and the associated trade flows are the lifeblood of the U.S. economy. By providing access to international markets, U.S. seaports support economic activities that in 2016 had a total economic impact to the national economy that exceeded $3.6 trillion and supported more than 20 million jobs. The volume of traffic and the value of exports and imports at U.S. seaports is expected to double by 2021, and double again shortly after.

Today's ships are moving through U.S. ports with little room under their keels -- in some cases, less than one foot. As vessel drafts increase and channel depths remain the same or increase to some degree, the navigation margins become smaller and the need for more accurate positioning information increases. The "just-in-time" supply chain upon which the U.S. economy depends demands that ports operate continuously, i.e., 24 x 7. However, delays and lightering due to the uncertainties posed by environmental factors can equate to millions of dollars a year in lost revenue for shipping companies and ports; this lost revenue extends to the economy. Unfortunately, the tools currently available to mariners for making safe operational decisions have not changed significantly over the last twenty years forcing increased vessel load and wait times in ports.

NOAA’s precision navigation program seamlessly integrates high-resolution bathymetry, high accuracy positioning and shoreline data with real-time predictions, and forecast data—such as water levels, currents, salinity, temperature, waves, and weather forecasts—to provide our data in a format that could be easily accessed and integrated into maritime portable pilot units or decision support tools. As a result, mariners will be better equipped to make critical navigation decisions. Since precision navigation involves many types and sources of data, it is a coordinated effort across several NOAA offices, including the Office of Coast Survey (OCS), the Center for Operational Oceanographic Products and Services (CO-OPS), the National Geodetic Survey (NGS), the U.S. Integrated Ocean Observing System (IOOS), and the National Weather Service (NWS).

Case Study - 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 port achieved the long-term goal to transit 69’ drafts safely. Lightering offshore is no longer required, improving operational efficiencies, safety, and reduce environmental risk.

Current Projects

NOAA is currently conducting two precision navigation port projects in the Lower Mississippi River and New York/New Jersey.

The Lower Mississippi River Complex is made up of the five ports including of New Orleans, Greater Baton Rouge, South Louisiana, and Plaquemines. The largest port cluster in the United States, providing a gateway to Latin America, Northern Europe, and the Mediterranean, also provides access to the inland waterway system and intermodal connections to rail and highways. This complex systems is susceptible to significantly changing water levels, low under-keel and air gap clearances, wave dominated approaches, strong currents and bends near Southwest Pass, and fog is a frequent challenge. In fact, a ship struck a bridge in 2018 re-routing all traffic 60 miles to closest bridge crossing.

The ports of New York/New Jersey encompasse the area from the sea buoy up the Hudson River to Troy, NY. It is the largest port on the East Coast, and the third-largest in the nation. High resolution hydrographic surveys have been completed for this stretch of water. Challenges to navigation are constrained spaces, complex currents, and low under-keel clearances.

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: 2/27/2019