Much like on the roads, boats follow a set of rules in order to prevent collisions. These rules identify which vessel must stay clear, but it is critical to note that nowhere in the navigation rules will you see the words right-of-way used. This is because all collisions are avoidable and even if you are the vessel that is not required to stay clear, you must take action to avoid a collision if the other boat has not.
Although very similar, it is also worth noting there are two different sets of rules. One is for vessels in inland waterways and one for international waterways. Once you cross the line of demarcation (Point Loma to Zuniga Jetty for San Diego) you are no longer in inland waters.
Most of you will know the basics but here is a more in depth look at the rules of the road.
When Two Boats Meet- Order of Stand On
Vessel Not Under Command: A vessel that has exceptional circumstance that makes her unable to maneuver.
Vessel Restricted in her Ability to Maneuver: A vessel which, from the nature of her work, is restricted in her ability to maneuver.
Vessel Constrained by Draft: 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.
Vessel Engaged in Fishing: A commercial vessel fishing with nets, lines, trawls, or other fishing apparatus which restrict maneuverability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict maneuverability.
Sailboats: Any vessel under sail provided that propelling machinery, if fitted, is not being used.
Powerboat: Any vessel propelled by machinery.
Seaplane: An aircraft that is designed to maneuver on the water.
Overtaking: A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam.
This order of stand on means that if you are a sailboat, you give way to all the vessels listed above sailboats and stand on to those listed below you.
Need help remembering that order? Use this mnemonic.
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When Two Sailboats Meet
Port/Starboard: The sailboat that is on a port tack shall give way to a sailboat that is on a starboard tack.
Same Tack: If two sailboats are approaching on the same tack, the sailboats which is to windward shall give way to the sailboats to leeward.
Remember P.O.W for sailboats meeting. Port, overtaking, and windward (on the same tack) are all the give way vessels when two sailboats meet.
When Two Powerboats Meet
Head On: When two powerboats are meeting head on, both are required to alter course to starboard in order to pass on each other’s port side.
Crossing: When two powerboats are crossing, the boat which has the other to its starboard shall keep clear. If possible, the give way boat shall not cross in front of the other vessel.
Note: A sailboat is no longer a sailboat when the engine is engaged, they are now a powerboat.
Responsibilities of Give Way and Stand on Vessels
First, vessels must always maintain a proper lookout and operate at a safe speed. Further, no rules exonerate a vessel or skipper from avoiding a collision.
When vessels meet, the give way vessel must make an obvious and early course or speed change to keep well clear of the stand on vessel. The stand on vessel must maintain its current speed and course to allow the give way vessel to give appropriate space. If a collision is unavoidable due to the inactions of the give way vessel, the stand on vessel must take action to avoid a collision.
For some bedtime reading, purchase a copy of the navigation rules or download the PDF version here. The navigation rules are commonly referred to as the COLREGS standing for Convention on the International Regulations for Preventing Collisions at Sea, 1972.
Stay safe and have fun!