Port & Harbor Operations

The Captain of the Port (COTP) is the senior USCG officer responsible for port safety and security within a defined geographic zone. COTP orders carry the force of federal law and may restrict or prohibit vessel movements, require vessels to remain in port, or direct a vessel to an anchorage or inspection facility. Failure to comply with a lawful COTP order is a federal violation. The COTP zone boundaries are published in 33 CFR Part 3.

Vessel Traffic Service (VTS) is a marine traffic monitoring and management system operated by the USCG. VTS systems exist in Puget Sound (VTS Seattle), San Francisco Bay, Houston-Galveston, New Orleans, New York/New Jersey, Prince William Sound, and Berwick Bay. Participation is mandatory for vessels 300 gross tons or more, vessels certificated to carry 50 or more passengers, and commercial towing vessels 26 feet or more in length operating within VTS areas. Mandatory VTS vessels must establish radio contact on the designated VTS channel before entering the VTS area and report at each required reporting point.

Compulsory pilotage requires that a vessel engage a state-licensed harbor pilot when entering or departing certain ports and waterways. Requirements are set by individual states, not the federal government, and vary by port. Foreign flag vessels and certain U.S. vessels over specified tonnage thresholds are typically subject to compulsory pilotage. The state-licensed pilot takes the conn (command of navigation) but the master retains overall command and responsibility for the vessel. If a compulsory pilot causes damage through negligence, the shipowner is generally not liable under the established pilotage exemption doctrine.

When calling VTS Seattle (Puget Sound VTS), a vessel must report: vessel name and call sign, current position, destination and estimated arrival time, vessel type and draft, any hazardous cargo, number of persons on board if a passenger vessel, and any vessel deficiencies affecting safe navigation. Reports are made on VHF-FM Channel 14 (primary) or Channel 5A. Reporting points are published in the VTS regulations. Vessels must also report any significant change in estimated time of arrival and any navigational hazards observed.

Port State Control (PSC) is the system by which a country inspects foreign-flagged vessels in its ports to verify compliance with international maritime conventions including SOLAS, MARPOL, MLC, and STCW. The USCG conducts PSC inspections in U.S. ports. Inspectors examine certificates, crew documentation, safety equipment, fire safety systems, stability information, navigation equipment, and pollution prevention measures. Deficiencies are classified by severity. A vessel may be detained (not permitted to sail) until serious deficiencies are corrected. Repeated deficiencies can result in a vessel being banned from U.S. ports.

Maritime Security (MARSEC) levels are set by the Coast Guard under the authority of the Maritime Transportation Security Act (MTSA) and align with the international ISPS Code. MARSEC Level 1 is the normal operating level with standard security measures in effect. MARSEC Level 2 is heightened security in response to increased risk, requiring additional protective measures. MARSEC Level 3 is the highest level, declared in response to a specific, credible threat, requiring exceptional security measures. The COTP sets MARSEC levels for ports and facilities within their zone. Vessels must coordinate with facilities to ensure matching security levels before port entry.

Under OPA 90 and 33 USC 1321, any discharge of oil into navigable U.S. waters must be reported immediately to the National Response Center (NRC) at 1-800-424-8802. The report must be made as soon as the person in charge has knowledge of the discharge. The report should include: location of the discharge, source and cause, material discharged, estimated quantity, and actions being taken. Failure to report is a federal criminal offense. The responsible party is also required to notify the COTP and may be directed to initiate cleanup operations immediately. The minimum reportable quantity for oil is any amount that causes a sheen on the water.

Squat is the dynamic sinkage of a vessel caused by the pressure differential created between the hull and the seabed in shallow water. As a vessel moves through restricted water, water flowing beneath the hull accelerates (Bernoulli effect), reducing pressure and causing the bow or stern (or both) to sink deeper than at rest. The amount of squat increases with vessel speed and decreases with water depth — specifically, the ratio of water depth to vessel draft (h/T ratio). A rule of thumb is that squat in feet approximately equals the block coefficient times the speed in knots squared divided by 100. Squat is a major grounding hazard and is why vessels slow down in shallow channels.

Bank suction occurs when a vessel passes close to a canal bank or channel edge. The water between the vessel and the bank accelerates (reduced pressure), causing the stern to be pulled toward the bank while the bow is simultaneously pushed away. Bank cushion is the opposite effect at the bow — the water ahead of the bow is compressed against the bank and pushes the bow away. Together, these effects can cause the vessel to sheer unpredictably. The remedy is to reduce speed and increase the distance from the bank. Tugs may be used to maintain position in narrow channels.

Rule 9 (Narrow Channels) requires vessels to keep to the starboard side of a narrow channel or fairway when it is safe to do so. Vessels shall not cross a narrow channel if doing so impedes a vessel that can only navigate within the channel. A vessel less than 20 meters or a sailing vessel shall not impede a power-driven vessel navigating in a narrow channel. Rule 34 (Maneuvering and Warning Signals) governs whistle signals in sight of one another: one short blast means altering course to starboard, two short blasts means altering course to port, three short blasts means operating engines astern. In meeting situations in port approaches, vessels must agree on the manner of passing using whistle signals or VHF radio communication.

Under 33 CFR Part 160, vessels arriving in U.S. ports must submit a Notice of Arrival (NOA) electronically through the National Vessel Movement Center (NVMC) system. The advance notice requirement is 96 hours before arrival for most vessels 300 gross tons or more and certain other vessels. If the voyage is less than 96 hours, the NOA must be submitted before departure. The NOA must include vessel particulars, crew and passenger lists, cargo information including any hazardous materials, and last port of call. For vessels arriving from foreign ports, CBP EAPIS (Electronic Advance Passenger Information System) is also required for crew manifests.

Port authorities are typically state or local government entities that manage port facilities, berth assignments, terminal operations, and commercial activities within the port. They regulate the use of port property and may set local operating rules. The USCG has federal jurisdiction over vessel safety, navigation, environmental protection, and port security within U.S. navigable waters. In practice, both authorities operate concurrently. The USCG sets safety and security requirements; the port authority manages commercial operations. The COTP has ultimate authority over vessel movements for safety and security purposes, even within the port authority's jurisdiction.

Spring lines run diagonally fore and aft from the vessel to the dock to prevent the vessel from moving forward or backward along the dock. A forward spring (leading aft from the bow area) prevents the vessel from moving forward. An after spring (leading forward from the stern area) prevents the vessel from moving aft. By holding a spring line and working the engine against it, the crew can swing the bow or stern in or out. For example, putting the engine ahead with an after spring made fast will kick the stern away from the dock. Spring lines are typically the first lines used to control position after making initial contact with the dock.

Tug assist requirements vary by port, vessel size, draft, and cargo type. Many ports require tugs for tankers carrying petroleum products or LNG above certain sizes. Some port regulations require tug escort for vessels over specified lengths even if the tug is not made fast. Communication with the tug captain should be established on an agreed VHF working channel before any maneuvering begins. A pre-arrival conference should cover the docking plan, spring line procedures, propeller wash dangers, and emergency signals. In U.S. harbors, the tug captain is generally considered a servant of the vessel being assisted, placing liability on the assisted vessel for tug-caused damage.

The International Ship and Port Facility Security (ISPS) Code is an IMO framework adopted after September 11, 2001, requiring vessels and port facilities to implement security plans. Vessels subject to SOLAS must have a Ship Security Plan (SSP) and a designated Ship Security Officer (SSO). The SSP must address access control, restricted areas, cargo and ship stores security, handling of unaccompanied baggage, monitoring of the vessel, and security communications. In U.S. ports, the ISPS Code is implemented through the Maritime Transportation Security Act (MTSA) and 33 CFR Parts 101-107. Vessels must ensure their security level matches or exceeds the security level of the port facility before conducting cargo or passenger operations.

Vessel interaction (also called hydrodynamic interaction) occurs when two vessels pass close together at speed. The pressure fields around each hull interfere, causing the vessels to be attracted to each other (bow to stern) and repelled (bow to bow). This effect is strongest in shallow, restricted water where the pressure fields cannot dissipate. A small vessel overtaken by a large vessel may be drawn toward the large vessel and lose steerage. The primary prevention is adequate speed reduction and maintaining maximum practical separation. COLREGS Rule 8 requires any action to avoid collision to be taken in ample time. In narrow channels with opposing traffic, both vessels should be at the slowest speed consistent with safe navigation.