How do harbor pilots guide huge ships into port?

A harbor pilot is a local navigation expert who climbs aboard a ship at the edge of a port, goes to the bridge, and tells the crew how to steer through channels, bends, currents and traffic to the berth. The pilot works with tugboats, shore line handlers and traffic controllers. The ship's captain keeps legal responsibility throughout. [1] [2]

Days ahead, the ship's agent usually arranges the pilot, tugs and line handlers. On arrival, a pilot boat carries the pilot to a boarding station in open water. In Saint John, New Brunswick, that is a set of coordinates almost five kilometres past Partridge Island, according to [cbc.ca](https://www.cbc.ca/news/canada/new-brunswick/port-saint-john-jobs-1.6862612). The pilot climbs a rope pilot ladder, which CBC says can rise up to nine metres above the water. One maritime article puts the climb at fewer than nine metres, and says some ships instead open a boarding hatch with a short ladder, as described by [marine-pilots.com](https://www.marine-pilots.com/articles/315201-vessel-pilots-ensuring-safe-port-calls). The pilot boat usually approaches on the lee side, where wind and waves are reduced. [3] [4] [1]

Once on the bridge, the pilot plugs a portable unit into the ship's electronic chart system and holds a pilot exchange with the master. The master describes the destination, the ship's characteristics, who is on the bridge, their first language, and the air draft, which shows whether the ship can pass under a bridge. The pilot then instructs the officer of the watch or captain during complex manoeuvres. A pilot can also refuse to proceed or halt operations if conditions are unsafe or the vessel is not fit to transit, which happens often in fog, according to [stories.tamu.edu](https://stories.tamu.edu/news/2024/03/26/how-captains-and-harbor-pilots-safely-guide-ships-into-port/). [2] [4]

Pilots rely on charts, radar, GPS, tide data, depth sounders and radio contact with tugs and vessel traffic services. Local knowledge of currents, sandbars and harbor rules remains essential, and conditions can change after storms or construction in ways charts do not show. [1] [4]

Large ships have deep drafts, long stopping distances and little room to turn. A rudder works well only when water flows past it, so very low speed reduces steering control, while extra speed makes mistakes harder to correct. A ship begins a turn well before the bend because its hull keeps moving after the helm changes. Wind can push high-sided container ships away from a berth, and currents can carry a vessel across a channel. [1]

Tugs help at low speeds, typically around five knots or less, pushing or pulling on the pilot's instructions. The number used depends on the ship's size and the wind. At the dock, line handlers secure the ship. In Saint John, markings at one-metre intervals on the asphalt help them relay the ship's position to the bridge, and pilot Gary Joyce says the margins are inches. [4] [3]

Pilots are usually certified by a state or federal government and act as advisers, so the master retains full responsibility for the ship. CBC describes the pilot as taking the conduct of the vessel, and one maritime article says the pilot assumes the conn. Another source notes that a captain would be unwise to ignore a pilot's recommendations. Bridge officers also check the pilot's advice against their own instruments and the ship's handling limits. [2] [4] [3] [1]