REON, Knots and River Pilots: Tradition Meets Innovation on the Hudson

The River’s Best Engineers Help the River’s Best Navigators, in Real-time

New York State law requires that a Hudson River pilot be aboard any foreign flag vessel, such as the oil tankers and container ships commonly seen on the Hudson, and any registered American ship of 300 gross tons and drawing seven feet, whenever those vessels operate in the New York portion of the river. Once aboard, the pilot, who is an expert rivernavigator and seasoned captain, has command over all navigation decisions made by the master of the vessel.

Hudson River pilot boat “Ambrose.”

Hudson River pilot boat “Ambrose.”

Hudson River Pilots are long-time but lesser known personages in Hudson Valley history and culture. They are true river experts. To become licensed by the Board of Commissioners of Pilots of the State of New York, a prospective river pilot must have many years experience as a licensed captain, particularly on the Hudson. He must know every Coast Guard rule, understand the workings of all manner of vessels from 650-feet in length to tugboats, and create from memory a map of the entire navigable Hudson with each of its hazards, the names of its reaches and landmarks, and aids to navigation.  Every year, a pilot’s “vision, medical records, training and work performance are reviewed in detail.” Most pilots descend from a line of pilots.

Pilots are responsible for the safe delivery of a ship, its cargo and crew. They have a language all their own for the Hudson and its hazards. For example, Kingston, NY is known as the “point of no return.” For a northbound ship, Port Ewen is the last location that provides a safe anchorage outside the navigation channel. Once past Kingston, the ship is committed to a narrow channel that extends to Albany. There is no room to turn around, no safe place to anchor and no space to allow another ship to pass.

Loading a container ship, Port of Albany.  Dennis W. Donohue via Shutterstock.

Loading a container ship, Port of Albany. Dennis W. Donohuevia Shutterstock.

The tides and currents are of special interest to pilots, and to shipping companies. A well-planned trip saves money through the practice of “fair tiding” — timing river currents, which change direction approximately every six hours, to give an additional push to a ship’s heading.

Pilots know the river’s peculiarities by heart — its shoals, reefs, and blind curves. They know of an upcoming navigation buoy, and the danger it might mark, long before it is reached. By contrast, tug captains who have no Hudson River experience can be seen at night trying to determine their location by scouring the river with spotlights, in search of the next buoy. Pilots deride this practice as “buoy hopping” and criticize it for hampering night vision.

But no matter how much one knows about the Hudson in advance, conditions that change daily can spell the difference between a safe delivery and an unsuccessful one. No published information or chart can predict with pinpoint accuracy the actual river conditions on a given date.

In the 19th century, vessel speed was calculated by timing knots as they were let out on a line. Below, our REON team deploys a sensor array that is towed behind a Clarkson University vessel.

In the 19th century, vessel speed was calculated by timing knots as they were let out on a line. Below, our REON team deploys a sensor array that is towed behind a Clarkson University vessel.

The River and Estuary Observatory Network (REON) research team recognized this problem and is working with the Hudson River Pilots Association to make REON data more accessible, starting with its acoustic doppler current Profiler (ADCP) in Albany, at the Dutch Apple dock. The ADCP provides real-time readings of the speed and direction of the river current — crucial information for the difficult entry into the Port of Albany, where the narrow channel is a challenge to the navigation of long, deeply loaded ships.

As often happens, the data had to be translated into a usable form – not as simple as it might sound. Our REON engineers use the metric system and typically express the speed of currents in centimeters per second, which is arcane enough for most of us. But the pilots have the engineers beat: they use “knots,”  a measurement that dates to a mid-19th century ship’s method of determining speed. Knots were tied into a line, placed at a distance of 47 feet, 3 inches and let out as it was measured against a 30-second sand-glass. A knot, or one nautical mile per hour, is equal to 1.852 kilometers per hour or 1.51 miles per hour.

Of course, our REON engineers, habitual and eager problem solvers to a person, also love the old methods. They have converted the Dutch Apple REON data into knots, so that Hudson River Pilots can regularly access accurate river speed and direction in real-time through the Beacon Institute website.