What must both vessels do when seeing a red, green, and white light at night?

When two vessels encounter a red, green, and white light at night, it indicates that they are nearing each other and must give way to avoid a collision. This specific combination of lights typically suggests that one vessel is operating under the rules as a powered vessel, while the other could be a sailing vessel or may also be under a different set of navigation rules.

The responsibility to give way is crucial because it helps ensure safe navigation on the water, allowing both vessels to alter their speed or course as necessary. It avoids confusion and reduces the risk of accidents in the limited visibility conditions typically present at night.

Understanding the navigation lights and their meanings is vital for boat operators, as it helps them respond appropriately when they encounter other vessels. This rule stems from international maritime rules designed to prevent collisions by establishing clear right of way protocols between different types of vessels.