When does a sailing vessel have the right of way over a power-driven vessel?

A sailing vessel has the right of way over a power-driven vessel when both are on a collision course, and the sailing vessel is on the windward side. This situation is governed by the International Regulations for Preventing Collisions at Sea (COLREGs), specifically Rule 12, which deals with sailing vessels.

In sailing, the windward side refers to the direction from which the wind is coming. A sailing vessel that is sailing into the wind (on the windward side) is considered to be constrained by her sails and has priority over a power-driven vessel when trying to avoid a collision. This rule is in place to facilitate safe navigation and to minimize potential conflict between different types of vessels.

Other scenarios mentioned may not provide a basis for the sailing vessel's right of way. The size of the vessel or whether it is in a narrow channel does not inherently grant the sailing vessel priority. Also, if a sailing vessel is operating under engine power, it loses its status as a sailing vessel, which could change the right of way dynamics as prescribed by the COLREGs. Therefore, the situation where both vessels are on a collision course, with the sailing vessel on the windward side, clearly supports the rule regarding the right of way.