Precision Marine Navigation

Smart solutions for mariners, in port and at sea

By Craig Collins

When NOAA’s Office of Coast Survey announced it would phase out production of paper nautical charts in December 2019, it was a bittersweet announcement. Established by President Thomas Jefferson in 1807 and known variously over the years as the Survey of the Coast, U.S. Coast Survey, U.S. Coast and Geodetic Survey, and, since 1970, as NOAA’s Office of Coast Survey, it has been providing nautical charts to the nation for 212 years. The charts were icons of coastal America and NOAA’s oldest mission: to survey and map the nation’s coasts for mariners.

Cartographer Julio Castillo reviews controlling depths in the Canaveral Barge Canal in Florida on ENC US5FL82M.

Paper charts are no longer particularly useful, despite their handcrafted beauty: the U.S. Coast Survey was only a few decades old when its hydrographic surveyors realized the seafloor was not a static environment. Underwater topography – bathymetry – changes constantly in response to natural and human-related activity; with the movement or deposition of shoals, rocks, wrecks and other objects.

Paper charts (or “raster charts” as they’re called when displayed on a monitor) can’t account for these changes – and yet the Coast Survey’s nautical charts support the transit of 1.3 billion metric tons of cargo, valued at $1.8 trillion, that enters and leaves U.S. ports every year. The Office of Coast Survey maintains charts covering 95,000 miles of shoreline and 3.6 million square nautical miles within U.S. coastal waters and its Exclusive Economic Zone.

NOAA’s Precision Navigation Data Gateway for users to discover, visualize, and disseminate NOAA marine products and services.

In the 1990s, NOAA hydrographers began to introduce a new chart platform, the electronic navigational chart (ENC), that integrated important information into the bathymetric display: a ship’s position, speed and draft (the distance from the waterline to a vessel’s keel), for example, along with GPS and weather data. ENCs are rapidly becoming the worldwide standard for navigation – “smart” charts with the ability to detect hazards, estimate how long it would take to encounter them, and automatically sound an alarm.

But according to Rear Admiral Shepard Smith, Director of the Coast Survey, ENCs have room to improve: They’re still limited by the amount of hydrographic information contained in paper charts. “About five years ago we broke that linkage,” Smith said, “and started to develop ENCs that contained richer information, and became the primary version of the chart in that area.” Many coastal areas, he said, required a greater level of detail: “The Intracoastal Waterway needed more information in order to be able to show the shoals within those narrow waterways. We needed larger scale coverage in Western Alaska, in order to support the community resupply requirements.” The ENC transformation initiative will deliver high-resolution gridded bathymetric maps that will overlap and display seamlessly, scrolling along at scale as mariners traverse the coasts.

The ability to provide highresolution bathymetry has significant implications for the capacities of cargo and tanker vehicles, Smith said: an extra foot of draft allows an oil tanker to carry up to 40,000 additional barrels into port. In the Port of Long Beach, California – where tankers often require some offshore offloading, or lightering, before safely berthing – this has been a crucial hindrance.

The Port of Long Beach. The Precision Marine Navigation Program at Long Beach has allowed ships to maximize their drafts without incurring additional risk entering the port.

The Office of Coast Survey piloted a new initiative, the Precision Marine Navigation program, that became operational in Long Beach in 2017. “We can show the slumping on the side of the channel, or the shoaling in some particular areas, at a level of detail that allows for precise navigation of shipping to be able to maximize their draft while not incurring any additional risk,” Smith said. “This has billions of dollars of importance for the capacity of our ports.”

The Port of Long Beach.

The Precision Marine Navigation program repackages NOAA’s marine navigation data into formats usable by navigation systems. These data include high-resolution bathymetry and environmental data with positioning, shoreline and weather forecast data, and will include real-time oceanographic and meteorological datasets. This more complete data package enables deep-draft vessels to navigate from the outer reaches of the harbor to the pier where they will tie up more safely and efficiently. After implementing the program in Long Beach, vessels expanded their usable draft from 65 to 69 feet – enabling tankers, for example, to stop offshore lightering and bring in up to 160,000 more barrels of product into port per ship. The Long Beach case study demonstrated the benefits of integrating NOAA’s datasets and provided the catalyst for more widespread implementation of the Precision Marine Navigation program.

“Other projects are in active development,” said Smith. “The potential for these next-generation navigation services is really enormous.”