SH Cap. 12 — Vessel Operations

1. Overview

Chapter 12 closes the book by stepping back from individual maneuvers to the overall operation of the vessel in pilot waters: how the passage is planned, what tools the bridge needs, and how the shiphandler keeps situational awareness from the open sea right up to the dock. The epigraph warns that many officers perfect their deep-sea navigation, where the ship is not endangered, yet make no effort to learn the tides, currents, and local conditions of the approach — leaving that to the captain or pilot. "This is where danger really exists."

The chapter is built around one recurring idea: every modern aid — the course card, ECDIS, a well-designed bridge, a pilot's DGPS laptop — is a tool that supplements good seamanship, not a substitute for it. The passage plan is a formalized dead reckoning; ECDIS data must be verified manually; the pilot, however accurate the laptop, must still look out the window. Underlying every section is the demand that the mariner stay actively in command of the operation rather than blindly follow a plan or a screen.

2. Planning the Passage

Passage planning is neither new nor any less important today, whether the passage is offshore or in pilot waters. The author makes a pointed argument: the need to plan does not diminish with experience on a route. The very person who plans most thoroughly is the pilot who has made a thousand trips over the same water — the planning only looks effortless and sketchy because of that deep local knowledge. The pilot checks currents and tides at several points, not just at the pier as the unpracticed mariner tends to do, compares dead reckoning to actual position continuously, and reviews notices to mariners even for long-familiar aids. If the expert plans this carefully, the less-familiar mariner should plan at least as carefully.

2.1 The Tabular Plan

The at-sea passage plan begins as an abstract tabular format. Ten items belong in it.

2.2 The Graphic Plan on the Chart

This same information goes onto all the necessary charts, and the graphic plan is more important than the tabular plan because good practice puts all navigation directly on the charts. As the plan is laid down, the charted data is compared against the table to catch errors or unforeseen dangers. The fixed elements — distances, courses, expected currents, arcs of visibility — are put on the chart in ink so they remain in original form for the whole passage and for future passages, avoiding the cumulative errors of continually shifted pencil courses. Daily navigation is done in pencil for comparison against the inked plan.

Pilot or inland waters call for extra information: courses and distances in each reach or leg; each turning point with a reference buoy or a bearing and distance off a prominent aid; set and drift at several significant points; times of high and low water at those points; the location of anchorages, pilot boarding areas, and where tugs are met and made fast; and shoals and hazards highlighted for the navigator's attention. Again everything except the times of tides and current changes is inked, so the work is not lost when the chart is erased.

2.3 The Hazard of Overplanning

Planning has a dangerous opposite extreme. The hazard of overplanning — and worse, of following an inflexible plan regardless of developing conditions — must always be considered. Do not plan the placement of every mooring line and then blindly follow that plan despite a 30-knot wind that springs up off the dock, or a freshet running across the berth. One mate followed an overly detailed plan until the bow was 50 feet over the Cristobal breakwater; pilots routinely find bridge teams frozen because another ship has stopped on the preplanned track "we have to follow."

The plan is meant only as a formalized dead reckoning and does not replace good seamanship, navigation, and shiphandling ability. — MacElrevey, ch. 12

3. The Course Card

In addition to the chart, the master prepares a pocket-size course card for reference during the passage to or from the dock. Its purpose is to minimize distraction: with the card, the master can stay at the centerline window to conn the ship or observe the pilot's work, instead of shifting between the wheelhouse and chartroom. The reasoning is simple — the pilot carries a course card even though he can draw the chart of the port from memory, so the master, with far less local knowledge, certainly needs one.

The card lists the reaches in order, each with its course, length, turning point, and the characteristics of the turning-point lights. It is put on one or two 3-by-5-inch cards kept in the shirt pocket, and it must cover the entire area between sea and dock — not just the portion run without a pilot. The card supplements the charts; it does not replace them. It is most appreciated when a heavy rain squall or fog sets in midway down the river and the master need only glance at it to check the heading as the ship feels her way to sea.

4. ECDIS

Paper charts are rapidly being replaced by the Electronic Chart Display and Information System (ECDIS). In many ways it is superior: real-time vessel position is shown in the wheelhouse where navigators can reach it, charts update automatically to the most current data, and a full set of up-to-date charts can cost less than maintaining a paper chart library. But the equipment must be used by trained, competent officers, and — unlike paper charts, which were common to all ships — the ECDIS aboard each vessel may be starkly different. A newly signed mate cannot be expected to be familiar with a ship's particular equipment on first sailing, and pilots may have limited time with all of its features.

4.1 Issues the Mariner Must Watch

Several problems demand alertness. Data may be input incorrectly — a wrong GPS-antenna position makes the vessel's position inaccurate, and a speed-log error corrupts the predicted position. The computer rule applies: "garbage in, garbage out." Because users choose which information layers are displayed, what one user deems unimportant may be essential to another, and users must know which features have been turned off.

A real-life problem is information overload: managing and filtering the display can be so time-consuming as to detract from navigation, and frequent alarms are so often ignored that crews tune them out entirely. ECDIS has aided passage planning in some ways but made it slower in others — for example, prominently displaying information for parallel indexing takes more time on ECDIS than on a chart. All the information previously listed as necessary for passage planning still applies, and crucially, any information supplied automatically must be verified manually.

5. Bridge Design

Good bridge design is essential if the mariner and shiphandler are to work safely and effectively; it is hard to use badly located equipment or to bring a ship onto a range hidden behind obstructions in the line of sight. The mariner must insist that naval architects give bridge design the same care given to hull and engine room, fitting the bridge to the deck officer's and pilot's work habits. Cost of installation should be secondary to good design, because the layout affects the ship's operation throughout her life.

An influential study was done in 1975 by a committee of master mariners and pilots chaired by Capts. Wilbur H. Vantine and Robert D. Valentine. It was adopted by the International Maritime Pilots' Association, reviewed and approved by over two hundred ship designers, builders, and owners, and included by IMO in the internationally accepted standards for bridge design. It presents design criteria rather than a standardized design, so present-day technology is not institutionalized — sensible, since a small bridge-controlled coaster docking with one man needs a more centralized layout than a VLCC or a 900-foot containership.

5.1 General Principles of Equipment Layout

Aboard new ships, miniaturized equipment should be grouped in clusters or stations that do not interfere with the shiphandler or watch officer. It is now possible to place all bridge equipment in one console, but that is counterproductive because several people must then crowd one area; gear should instead be grouped by use and each cluster placed where it is most useful. No two mariners agree on exact placement, yet experienced pilots and mariners concur on ten general principles.

5.2 The Helmsman's Station

Naval architects often misunderstand the helmsman's duties, so many modern ships put the wheel forward at the windows — and such ships seem inevitably to sign on a 7-foot-tall helmsman, making it impossible for the master or pilot to see. The helm station should instead be well back from the window, equipped with a gyro repeater, gyro pilot controls, rate-of-turn indicator, and wheel and rudder-angle indicators. If a ship's helm is wrongly placed at the windows, at least give the helmsman a stool to sit on in pilot waters so the conning officer can see over his head.

5.3 The Conning Station

The centerline conning station groups in one place all the equipment needed for shiphandling, with gear bulkhead-mounted over the windows and on a console aft of them, keeping access to the glass clear. An unobstructed view ahead and abeam matters most when light rain beads the windows and one must get right up to the glass to see. The optimum conning station would include a VHF transceiver, wind direction and force indicators, whistle control, Doppler speed indicators, digital fathometer, gyro repeater, tachometer, rate-of-turn indicator, rudder-angle indicator, and a radar/CAS display — so the mate or pilot gets every reading without moving about, which is vital because it is hard to stay oriented to ship motion, especially lateral motion, while walking from station to station.

A second radar/CAS and the ECDIS displays go to starboard of this location, so the horizon off the starboard bow is visible from the radar. Designers must also limit the glare from displays, which even fully dimmed diminishes night vision. A similar but smaller station goes on each wing — a tachometer, gyro repeater, VHF and internal-communications handsets, rudder-angle indicator, and bow-thruster controls — used when embarking or disembarking a pilot or conning alongside. Larger or noisy ships need an answerback communications system so the mate and helmsman can acknowledge orders, eliminating the shouting that causes misunderstood commands and accidents.

6. Bridge Height

Bridge height is a critical design consideration. One European containership class was put into service with a wheelhouse so low that the tops of the containers rose above the lower windows, making it physically impossible to conn from that location — the pilot ended up hanging over the wing like an old locomotive engineer. The wheelhouse must be raised, even at the cost of an extra unused deck, so the berth alongside and the area ahead are visible at a reasonable distance — especially important on bridge-aft ships, whose design already restricts visibility over the bow.

Working from great height carries its own trap: distance and speed of advance are greatly distorted as the height of eye rises. The ship appears to move much more slowly, and to be much closer to reference points, than she really is. A modern LNG ship's height of eye of 110 to 130 feet is like working from the roof of a ten- to twelve-story building.

6.1 Bridges Placed Forward

Automobile carriers, LASH ships, RO/RO vessels, and smaller passenger ships commonly put the wheelhouse very close to the bow — working just 75 feet from the stem makes turning rates hard to estimate. The remedy is to work looking aft, "Great Lakes fashion," in restricted areas, to provide a clear view to the stern from the wings and amidships, and to extend the wings to the ship's maximum beam so the parallel midbody is visible. A gunsight effect — a vertical jackstaff or pole at the bow lined up with a marker on the centerline window — makes small heading changes obvious. Since good shiphandlers watch the stern as much as the bow, a forward wheelhouse poses no real obstacle if the bridge is properly designed.

For every ship, prepare a visibility diagram showing the areas not visible from the wheelhouse in light and loaded conditions, with and without containers, and post it on the bridge. It is built with basic trigonometry from the ship's dimensions — bridge height, bridge-to-bow distance, beam — and is especially helpful when maneuvering around piers and in restricted channels.

7. Pilot Navigation Equipment

More and more pilots bring aboard laptop navigation systems designed for a particular port. Miniaturized electronics make the gear smaller, cheaper, and more portable, so software and features can be made port-specific and extremely useful — letting pilots operate in ice, fog, and conditions that once closed a port. The author stresses these are not off-the-shelf chart programs on a laptop: they are specially designed navigation systems with expensive equipment, programming, and upgraded charts, and pilot associations and ports treat the investment as repaying its cost many times over in safety and efficiency.

7.1 The CTAN System and DGPS — General

The leading example is the Panama Canal's CTAN(S) — Communications, Traffic Management, and Navigation System — developed in the late 1990s by a pilot team with the Panama Canal Commission and the Volpe Center in Cambridge, Massachusetts. Each pilot brings aboard a single case holding a combined satellite/UHF antenna, a laptop, and a unit combining a radio transceiver, DGPS equipment, and interfacing software. Within minutes the system supports DGPS navigation and exchanges radio data between ships through shore-based transceivers and repeaters.

The system processes the ship's movement from sequential DGPS positions to calculate location, speed, and course, then broadcasts that to a central location, where it is combined with data from all other vessels and rebroadcast to every ship at once. Each ship sends an identifier plus speed, course, draft, length, beam, antenna location, cargo type, and pilot name; this generates a to-scale graphic of every vessel on every screen, so pilots "see" actual ship locations and movements throughout the canal — not mere blips. Still, the standard caveat holds: DGPS laptops are additional aids, subject to breakdown, and will not detect a yacht or an off-station buoy that carries no system. Pilots must still look out the window.

7.2 Navigation and Piloting — Accuracy

These systems bring inland piloting to a new level: the channel axis and limits, charted buoys and ranges, and readouts of distance off the centerline and distance to a course change are shown graphically, letting trained shiphandlers navigate in restricted visibility, ice, or where aids are not visible. Pilots demonstrated this by taking ships through the winding eight-mile Gaillard Cut using only the laptop, making turns and adjusting for bank suction while standing in the chartroom.

The decisive limit is the chart: the charts are the limiting factor in accuracy and usefulness. Off-the-shelf electronic charts and handheld computers are convenient for routine navigation but not acceptable for the uses in this chapter; only special-purpose DGPS pilot systems on extremely accurate charts deliver the required accuracy on own-ship and other ships. Such systems are proven on the Delaware River, Tampa, the Chesapeake Bay, and elsewhere, keeping ports open in winter ice and letting ships move in fog when ranges and buoys are not visible.

7.3 Capabilities and Independence

Typical systems provide rate-of-turn indication; automatic, continuously adjusting calculation of ship meeting points; extremely accurate own-ship speed with graphic and audible readout (useful close-in, without the limits of Doppler); constant distance from centerline and to waypoints; weather, tide, and current broadcast from instruments; real-time tug and dock availability; ship-to-ship and broadcast email; direct readout of other ships' courses and speeds without radar's time delay; and range and bearing measured past bends and obstructions, along the channel axis. A key strength is independence from ship's equipment: the pilot's gear behaves identically from ship to ship, its condition is known, it adds redundancy, and it can be replaced quickly if it fails — a reason to minimize integration with shipboard systems, keeping them redundant rather than interdependent.

7.4 Shiphandling — Making Turns and Meeting Points

The DGPS system is also a shiphandling tool. For turns, radar users set the variable range marker (VRM) at a known distance and start the turn when it touches a reference point, using the electronic bearing line (EBL) to monitor progress. The DGPS method is similar but better: instead of VRM and EBL, the pilot uses the distance to the channel-leg intersection to start the turn and the distance off the next leg's centerline to adjust the rate of turn — and because the channel is shown independent of line of sight, the system "sees around corners." The start point is typically 2½ to 3 ship lengths from a turn, varying with ship size, hull form, current, speed, and even the individual pilot.

For meeting points, the better systems continuously show where tracked vessels will meet, calculating future positions from programmed channel courses at assumed constant speed. This differs fundamentally from a radar CPA, which assumes a straight-line course and is only useful in open water; the pilot system computes meetings along the curving channel, even through multiple turns and when ships cannot see each other. The pilot selects the ship being met, initiates the calculation, watches the meeting circle, and adjusts speed until the meeting falls in a safe spot — arranged within a couple hundred feet.

7.5 Traffic Management — Passive vs. Active

Two-way DGPS moves traffic management to a new generation in which the master or pilot has an active role, with better real-time data than a shore-side controller using traditional reporting. Traditional passive traffic management relays filtered information by radio, or via AIS on ECDIS or radar — filtered by procedure or the controller's judgment, which was the best process when those systems were designed.

With active management, meetings are arranged by the two shiphandlers themselves, based on weather, ship type, and the maneuvering characteristics of both vessels — by decision makers with firsthand, immediate knowledge — with no third party in the loop and no chance of the errors inherent in passive systems. Because laptop DGPS is not line-of-sight, active management by the shipboard user is appropriate in almost any port or channel: the bridge team watches movements miles away, around bends and behind hills, and knows the effect of every speed and course change. These systems supply the navigation aids recommended by the National Research Council Marine Board's 1994 report Minding the Helm.

8. Night Versus Day Maneuvering

Darkness creates new problems: there are really two pilotages in any water, a daylight one and a night one. Speed and distance are harder to estimate because depth perception is lost at night, so relative size and changes of relative motion must be used to judge distance; it becomes even more important to look abeam or aft, since speed cannot be judged by looking ahead in the dark. On a clear night objects appear closer, yet as visibility deteriorates they appear farther away. Unlighted buoys and shoreline disappear, forcing more reliance on radar and local knowledge, and a poorly lit stringpiece must be avoided by instinct during docking.

Even a small increase in light helps, since some depth perception returns; do not make a passage without computing moonrise and moonset, and given the choice delay a difficult passage until daybreak unless there is at least a gibbous moon. A more seasoned master often delays arrival until daylight when there is no real need to arrive earlier. Radar has largely removed the difficulty of judging distance at sea at night, but the shiphandler should still estimate distance by eye before going to the radar, to keep that skill sharp for when the radar fails or in a congested anchorage.

8.1 Substitutes for Depth Perception

Depth perception comes from binocular vision and unconscious evaluation of relative position; when it is lost at night the mariner substitutes other techniques.

The rate of change in relative bearing is especially useful: for a ship turning inside a buoy, the buoy's apparent motion grows sharply as distance decreases, so that change can estimate the changing distance off. Once more the lesson is to practice estimating distance before looking at the radar, and the skill of handling a ship at night comes quickly.

9. Record Keeping

Keeping logs and records of maneuvers is inherent in proper shiphandling, yet record keeping and navigation often conflict when the paperwork becomes redundant or overcomplicated. The priority is clear: give priority to navigation — it is more important to avoid a casualty than to record the exact time of impact. Good organization and the use of autologging relieve the mate of administrative chores; every ship should carry an automatic bell logger, since the mate's time is better spent checking the tachometer and rudder-angle indicator to see that orders are executed than continuously writing down the bells.

9.1 The Scratch Log

In pilot waters, limit all record keeping to one scratch log/workbook and the chart. Important data is transferred to the deck log later, so the mate need not shuffle bell books, navigation books, logbooks, and sounding books. Enter bearings directly into the scratch log rather than first onto scratch paper — which cuts logging chores by nearly fifty percent — and keep it neat but brief, since it is only a rough notebook for later reference. The deck log itself, however, must still record certain items.

9.2 Information Is for Use, Not Just Record

Note navigational information first on the chart, then put the essentials into the scratch log; compare each position with the dead reckoning and the inked courses, and report any set to the master and pilot. The point is emphatic: information is gathered so it can be supplied to the officer conning, not merely recorded for historical interest. Do not finish your duties writing down information while the vessel sets toward a shoal only you are aware of, and do not assume the pilot has seen it — tell him. Keeping the passage plan preplotted in ink nearby reduces record keeping and serves as a running check of actual progress against the plan.