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Title 33

Displaying title 33, up to date as of 9/15/2021. Title 33 was last amended 9/10/2021.

Title 33

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§ 161.2 Definitions.

For the purposes of this part:

Center means a Vessel Traffic Center or Vessel Movement Center.

Cooperative Vessel Traffic Services (CVTS) means the system of vessel traffic management established and jointly operated by the United States and Canada within adjoining waters. In addition, CVTS facilitates traffic movement and anchorages, avoids jurisdictional disputes, and renders assistance in emergencies in adjoining United States and Canadian waters.

Hazardous Vessel Operating Condition means any condition related to a vessel's ability to safely navigate or maneuver, and includes, but is not limited to:

(1) The absence or malfunction of vessel operating equipment, such as propulsion machinery, steering gear, radar system, gyrocompass, depth sounding device, automatic radar plotting aid (ARPA), radiotelephone, Automatic Identification System equipment, navigational lighting, sound signaling devices or similar equipment.

(2) Any condition on board the vessel likely to impair navigation, such as lack of current nautical charts and publications, personnel shortage, or similar condition.

(3) Vessel characteristics that affect or restrict maneuverability, such as cargo or tow arrangement, trim, loaded condition, underkeel or overhead clearance, speed capabilities, power availability, or similar characteristics, which may affect the positive control or safe handling of the vessel or the tow.

Navigable waters means all navigable waters of the United States including the territorial sea of the United States, extending to 12 nautical miles from United States baselines, as described in Presidential Proclamation No. 5928 of December 27, 1988.

Precautionary Area means a routing measure comprising an area within defined limits where vessels must navigate with particular caution and within which the direction of traffic may be recommended.

Towing Vessel means any commercial vessel engaged in towing another vessel astern, alongside, or by pushing ahead.

Published means available in a widely-distributed and publicly available medium (e.g., VTS User's Manual, ferry schedule, Notice to Mariners).

Vessel Movement Center (VMC) means the shore-based facility that operates the vessel tracking system for a Vessel Movement Reporting System (VMRS) area or zone within such an area. The VMC does not necessarily have the capability or qualified personnel to interact with marine traffic, nor does it necessarily respond to traffic situations developing in the area, as does a Vessel Traffic Service (VTS).

Vessel Movement Reporting System (VMRS) means a mandatory reporting system used to monitor and track vessel movements. This is accomplished by a vessel providing information under established procedures as set forth in this part in the areas defined in Table 161.12(c) (VTS and VMRS Centers, Call Signs/MMSI, Designated Frequencies, and Monitoring Areas).

Vessel Movement Reporting System (VMRS) User means a vessel, or an owner, operator, charterer, Master, or person directing the movement of a vessel that is required to participate in a VMRS.

Vessel Traffic Center (VTC) means the shore-based facility that operates the vessel traffic service for the Vessel Traffic Service area or zone within such an area.

Vessel Traffic Services (VTS) means a service implemented by the United States Coast Guard designed to improve the safety and efficiency of vessel traffic and to protect the environment. The VTS has the capability to interact with marine traffic and respond to traffic situations developing in the VTS area.

Vessel Traffic Service Area or VTS Area means the geographical area encompassing a specific VTS area of service. This area of service may be subdivided into zones for the purpose of allocating responsibility to individual Vessel Traffic Centers or to identify different operating requirements.


Although regulatory jurisdiction is limited to the navigable waters of the United States, certain vessels will be encouraged or may be required, as a condition of port entry, to report beyond this area to facilitate traffic management within the VTS area.

VTS Special Area means a waterway within a VTS area in which special operating requirements apply.

VTS User means a vessel or an owner, operator, charterer, Master, or person directing the movement of a vessel within a VTS Area that is:

(1) Subject to the Vessel Bridge-to-Bridge Radiotelephone Act;

(2) Required to participate in a VMRS; or

(3) Equipped with a required Coast Guard type-approved Automatic Identification System (AIS).

VTS User's Manual means the manual established and distributed by the VTS to provide the mariner with a description of the services offered and rules in force for that VTS. Additionally, the manual may include chartlets showing the area and zone boundaries, general navigational information about the area, and procedures, radio frequencies, reporting provisions and other information which may assist the mariner while in the VTS area.

[CGD 90-020, 59 FR 36324, July 15, 1994, as amended by CGE 97-023, 62 FR 33364, June 19, 1997; USCG-2003-14757, 68 FR 39364, July 1, 2003; USCG-1998-4399, 75 FR 66314, Oct. 28, 2010; USCG-2005-21869, 80 FR 5334, Jan. 30, 2015; 80 FR 17327, Apr. 1, 2015; USCG-2018-0874, 84 FR 30880, June 28, 2019]