In sailing, Navigation Rules (often called "Colregs" or "Rules of the Road") are a set of international and inland regulations designed to prevent collisions between vessels. These rules categorize boats into two roles when they meet: the Give-way vessel, which must take early and substantial action to keep clear, and the Stand-on vessel, which must maintain its course and speed.

Key Sailing Terms in Navigation Rules
Sailing Vessel: A vessel under sail that is not using its engine. If the engine is running, the boat is legally considered a "power-driven vessel" even if sails are up.

Starboard Tack: When the wind is blowing over the right (starboard) side of the boat. A vessel on a starboard tack generally has the right of way over a vessel on a port tack.

Port Tack: When the wind is blowing over the left (port) side of the boat. These vessels must typically "give way" to those on a starboard tack.

Windward: The side or direction from which the wind is blowing (upwind). In a meeting between two boats on the same tack, the windward boat must give way.

Leeward: The side or direction away from the wind (downwind). The leeward boat is generally the "stand-on" vessel when both boats are on the same tack.

Underway: A vessel that is not at anchor, made fast to the shore, or aground.