Revision Notes for Rule 3 of the International Rules for Prevention of Collisions at Sea (COLREGs)
Rule 3 of the COLREGs provides essential definitions that are foundational for understanding and applying the collision avoidance rules. This comprehensive guide covers each definition and explains their significance in maritime navigation.
1. Vessel
Definition:
- Any watercraft, including non-displacement craft, WIG (Wing-In-Ground) craft, and seaplanes, used or capable of being used as a means of transportation on water.
- Explanation: This broad definition ensures all types of watercraft are included under the COLREGs, which means the rules apply universally to everything from traditional boats to modern, high-tech crafts.
2. Power-Driven Vessel
Definition:
- Any vessel propelled by machinery.
- Explanation: Differentiates from sailing vessels and other non-powered vessel types, establishing specific rules for its navigation. Power-driven vessels must be aware of their responsibilities and interactions with other vessel types.
3. Sailing Vessel
Definition:
- Any vessel under sail, provided that propelling machinery, if fitted, is not being used.
- Explanation: Critical for understanding the right of way rules between power-driven and sailing vessels. Sailing vessels have different maneuverability characteristics that must be considered in navigation.
4. Vessel Engaged in Fishing
Definition:
- Any vessel fishing with nets, lines, trawls, or other fishing apparatus which restricts maneuverability.
- Explanation: Highlights vessels with restricted maneuverability due to fishing operations, which necessitates caution from other vessels to avoid collisions. Does not include vessels trolling or using other non-restrictive apparatus.
5. Seaplane
Definition:
- Any aircraft designed to maneuver on water.
- Explanation: Ensures that seaplanes follow similar collision avoidance rules when operating on water, integrating aviation with maritime navigation to maintain safety.
6. Vessel Not Under Command (NUC)
Definition:
- A vessel which, through some exceptional circumstance, is unable to maneuver as required by these rules and is therefore unable to keep out of the way of another vessel.
- Explanation: Vessels with compromised maneuverability need to be identified clearly to other mariners who must take appropriate action to avoid them. Recognizing an NUC vessel is vital for collision prevention.
7. Vessel Restricted in Her Ability to Maneuver (RAM)
Definition:
- A vessel which, from the nature of her work, is restricted in her ability to maneuver as required by these rules and is therefore unable to keep out of the way of another vessel.
- Explanation: RAM vessels include those engaged in operations like dredging, surveying, or underwater work. Other vessels need to provide them wide berth to ensure safe operations.
8. Vessel Constrained by Her Draft (CBD)
Definition:
- A power-driven vessel which, because of her draft in relation to the available depth and width of navigable water, is severely restricted in her ability to deviate from the course she is following.
- Explanation: Emphasizes the navigation challenges faced by deep-draft vessels. Other vessels must understand the limited maneuverability and adjust their actions accordingly.
9. Underway
Definition:
- A vessel is "underway" when it is not at anchor, made fast to the shore, or aground.
- Explanation: Differentiates vessels that are actively navigating from those that are stationary, ensuring that proper navigation rules are applied.
10. Length and Breadth
Definition:
- Length overall (LOA) and greatest breadth.
- Explanation: These dimensions are used in various regulations and calculations, such as determining safe passing distances and applying sound signals.
11. Vessel at Anchor
Definition:
- A vessel that is not moving and is held in place by an anchor or anchors.
- Explanation: Requires specific lights and shapes to indicate its status to other vessels, ensuring they navigate safely around the anchored vessel.
12. Restricted Visibility
Definition:
- Any condition in which visibility is restricted by fog, mist, falling snow, heavy rainstorms, sandstorms, or any other similar causes.
- Explanation: Calls for special navigational measures, such as using sound signals and reducing speed to prevent collisions in limited visibility conditions.
13. In Sight of One Another
Definition:
- Vessels are deemed to be "in sight of one another" only when one can be observed visually from the other.
- Explanation: Important for rules regarding right of way and actions to avoid collisions, as visual contact dictates specific navigational behaviors.
14. Traffic Separation Scheme
Definition:
- A routeing measure aimed at the separation of opposing streams of traffic by appropriate means and by the establishment of traffic lanes.
- Explanation: Ensures the safe and efficient movement of vessel traffic in congested or sensitive areas, reducing the risk of collisions.
15. Wing-In-Ground (WIG) Craft
Definition:
- A multimodal craft which, in its main operational mode, flies in close proximity to the surface by utilizing surface-effect action.
- Explanation: Ensures these craft follow both marine and aviation rules when necessary, integrating their unique operational characteristics into maritime navigation rules.
16. New Vessel
Definition:
- A vessel whose keel is laid or which is at a similar stage of construction on or after the date on which these Rules come into force.
- Explanation: Differentiates from existing vessels, ensuring that new constructions comply with the latest safety and regulatory standards.
17. Existing Vessel
Definition:
- A vessel that is not a new vessel.
- Explanation: Ensures clarity in applying transitional provisions of the rules, maintaining safety standards across all types of vessels.
18. International Voyage
Definition:
- A voyage from a country to which the present convention applies to a port outside such country, or conversely.
- Explanation: Determines applicability of various international maritime regulations, ensuring that vessels on international voyages adhere to the same safety standards.
Practical Considerations for Master Mariners
- Understanding Definitions: Thorough knowledge of these definitions is essential for correct application of the COLREGs.
- Navigational Safety: Proper identification of vessel status (e.g., NUC, RAM) ensures safe and effective communication and navigation, preventing collisions.
- Compliance with Regulations: Staying updated with these definitions ensures compliance with international maritime laws and regulations.