Navigation and Collision Avoidance Rules

Collision Avoidance

• Any alteration of course and/or speed to avoid collision should be large enough to be readily apparent to another vessel observing visually or by radar.
• A succession of small alterations of course and/or speed should be avoided.
• If there is sufficient sea room, alteration of course alone may be the most effective action to avoid a close-quarters situation.

Safe Distance

• Action taken to avoid collision with another vessel should result in passing at a safe distance.
• The effectiveness of the action should be carefully checked until the other vessel is finally past and clear.

Speed and Propulsion

• If necessary to avoid collision or allow more time to assess the situation, a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion.

Impeding Passage

• A vessel which is required not to impede the passage or safe passage of another vessel shall take early action to allow sufficient sea room for safe passage of the other vessel.
• A vessel required not to impede the passage or safe passage of another vessel is not relieved of this obligation if approaching the other vessel so as to involve risk of collision.

Narrow Channels

• A vessel proceeding along the course of a narrow channel or fairway shall keep as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.

Overtaking

• A vessel is deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam.
• When a vessel is in any doubt as to whether she is overtaking another, she shall assume that this is the case and act accordingly.

Head-on Situation

• When two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision, each shall alter her course to starboard so that each shall pass on the port side of the other.
• Such a situation shall be deemed to exist when a vessel sees the other ahead or nearly ahead and by night could see the masthead lights of the other in a line or nearly in a line and/or both sidelights.

Crossing Situation

• When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.

Action by Give-way Vessel

• Every vessel which is directed to keep out of the way of another vessel shall, so far as possible, take early and substantial action to keep well clear.

Action by Stand-on Vessel

• Where one of two vessels is to keep out of the way, the other shall keep her course and speed.
• The latter vessel may take action to avoid collision by her maneuver alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these Rules.

Responsibilities between Vessels

• A power-driven vessel underway shall keep out of the way of:
  • A vessel not under command
  • A vessel restricted in her ability to maneuver
  • A vessel engaged in fishing
  • A sailing vessel
• A sailing vessel underway shall keep out of the way of:
  • A vessel not under command
  • A vessel restricted in her ability to maneuver
  • A vessel engaged in fishing
• A vessel engaged in fishing when underway shall, so far as possible, keep out of the way of:
  • A vessel not under command
  • A vessel restricted in her ability to maneuver
• Any vessel other than a vessel not under command or a vessel restricted in her ability to maneuver shall, if the circumstances of the case admit, avoid impeding the safe passage of a vessel constrained by her draught, exhibiting the signals in Rule 28.