Applying two sets of collision-prevention rules
There are two sets of collision regulations (what the U.S. Coast Guard calls COLREGs) to guide vessels of all sizes: the International Regulations for Preventing Collisions at Sea and the U.S. Inland Navigational Rules.The Inland Rules apply to all vessels inside the demarcation lines separating inland and international waters; the International Rules apply outside the demarcation lines. These lines are shown on charts, but in their absence, the International Rules apply within bays, harbors, and inlets; along specified stretches of coasts; and up the connecting rivers to their limits of continuous navigation.By careful design, there are few differences in the two sets of regulations, and they mostly concern navigation lights and sound signals.Who, then, gives way to whom? In the following list, every vessel gives way to all other vessels listed before it:
- a vessel not under command
- a vessel restricted in her ability to maneuver
- a vessel constrained by her draft
- a vessel engaged in fishing
Three exceptions to this list are discussed later in this entry. Meanwhile, be aware that a “vessel not under command” is one
 |
| An at-a-glance guide to appropriate responses as set forth in the nautical rules of the road. |
that is unable to keep clear of another vessel
through exceptional circumstances. Such a vessel
must display the correct signal: two balls or similar shapes in a vertical line, or two all-around red lights in a vertical line by night.Similarly, a vessel that, from the nature of her work, is “restricted in her ability to maneuver”
must exhibit a ball, a diamond, and another ball in a vertical line; or, at night, a red light, white light, and another red light in a vertical line.A vessel “constrained by her draft”
may show three all-around red lights in a vertical row by night, or a cylinder (with the axis vertical) by day. She’s not obligated to make these signals, but if she has any sense, she
will.A vessel “engaged in fishing” is defined as one “fishing with nets, line trawls, or other fishing apparatus that
restricts maneuverability.” This rule specifically excludes vessels fishing with trolling lines or gear that doesn’t restrict maneuverability.Don’t forget that a sailboat using her engine in gear is regarded as a power-driven vessel, whether or not she has sail set.The three exceptions to the previous list are as follows:
- Rule 9 says a vessel of less than 66 feet (20 m) in length or a sailing vessel of any length must keep clear of any vessel that can navigate safely only within a narrow channel or fairway.
- Rule 10 says a vessel less than 66 feet in length or a sailing vessel of any size shall not impede the passage of a power-driven vessel following a traffic lane in a traffic-separation scheme.
- Rule 13 simply stipulates that the overtaking vessel shall keep clear—which means that if a sailboat starts overtaking a slow-moving power-boat, it’s the sailboat’s duty to keep clear.
If you’re in a powerboat and you intend to overtake another vessel in a narrow channel, you must correctly signal your intention and receive an acknowledgment. In a sailboat, you may overtake without signaling only in waters subject to the Inland Rules.See also
Fishing Boats; Sound Signals.
