The rules of the road (the COLREGs) exist so boats don't run into each other. You don't need the whole rulebook by heart, but a skipper who doesn't know the basics is a menace. This is the working version.
Who gives way
In any meeting, one boat is the give-way vessel and gets out of the way early and obviously. The other is the stand-on vessel and holds its course and speed so the first boat can plan around it. Here's the catch: the stand-on boat still has to act if the give-way boat does nothing. Nobody gets to sit there being right all the way to the collision.
The three encounters
- Head-on: two powerboats coming straight at each other both turn right (to starboard) and pass port to port, same as cars.
- Crossing: whoever has the other boat on their starboard side gives way. Think of it as yielding to traffic from your right.
- Overtaking: if you're catching someone from behind, you give way, every time, sail or power. Hoisting a sail doesn't buy you the right to barge past.
The sail-beats-power myth
People love to say sail always has right of way over power. It usually does, but the exceptions are the whole point. Everyone keeps clear of a boat not under command, one restricted in its ability to maneuver, or a ship hemmed in by its draft in a channel. And a sailboat running its engine counts as a powerboat, sails up or not.
Channels and darkness
Stay to the right (starboard) side of a narrow channel, and don't get in the way of a big ship that can't dodge you. After dark you tell boats apart by their lights: red to port, green to starboard, white showing aspect and type. Our guide to marks and lights goes deeper on that.
The rule that beats the rest
Underneath all of it, you're required to keep a proper lookout, run at a safe speed, and do whatever it takes to avoid hitting anyone, even if that means ignoring a rule. When you're not sure, slow down and make your move early and obvious, so the other guy can read you.