Collisions occur between boats more often than you might think, usually because one or both captains did not know or were not applying the Rules of the Road. The rules come from the International Regulations for Preventing Collisions at Sea (COLREGS), with which the U.S. regulations are consistent. Following are the basic rules that apply to all sailboats in U.S. waters.
Whenever two boats come close to each other, the rules designate one as the stand-on vessel and the other as the give-way vessel. The rules are designed to prevent a situation like two people walking toward each other on a sidewalk who both step out each other's way in the same direction and thus run into each other. The stand-on vessel must continue on its course and the give-way vessel must turn away to avoid collision. Therefore both captains must understand the Rules of the Road and know whether, in any given situation, their boat is to stand on or give way.
Sailboat vs. Sailboat
The Rules are simple when two boats meet under sail (engines not running), as shown in the illustration above:
- If the boats are on different tacks (sails on different sides of the boat), then the sailboat on the starboard tack (wind coming from the starboard side, with sails thus out to the port, or left, side) is the stand-on vessel and the boat on the port tack must give way. The port-tack boat must also give way to a sailboat whose tack is uncertain (such as when sailing downwind using a spinnaker).
- If the boats are on the same tack, the leeward (downwind) boat is the stand-on vessel, and the windward boat must give way.
In sailboat races there are additional rules about the start line, rounding marks, and so on, but the basic rules above apply when boats meet in open water.
Sailboat vs. Powerboat
Remember that a sailboat running an engine, even if sails are up, is legally categorized as a powerboat. In a congested area it is best not to run the engine with sails still up, because captains of other boats may not be aware of your engine running and may assume you are operating under sailing rules.
The Rules are simple when a sailboat and a small recreational powerboat meet:
- In most situations the sailing boat is the stand-on vessel and the powerboat must give way.
- If the sailboat is overtaking a powerboat, the powerboat is the stand-on vessel and the sailboat must give way.
- Any boat with more maneuverability must give way to any boat with less maneuverability (see below).
Maneuverability Is Key!
Sailboats under sail generally have right of way over most recreational powerboats, because sailboats are assumed to have more restricted maneuverability than powerboats (for example, a sailboat cannot turn and sail straight into the wind to avoid a collision). But by the same principle, sailboats must give way to any boat with less maneuverability.
This means that usually a sailboat must give way to a large ship. If you sail offshore or at night in fog, it's a good idea to have an inexpensive AIS system on your boat to help you avoid collisions.
Go on to the next page for maneuverability rules and the different rules when a sailboat is under power.