The color of a buoy indicating a wreck that must be left to the starboard side of a vessel is typically ______.

The color of a buoy indicating a wreck that must be left to the starboard side of a vessel is typically red. This is consistent with the International Association of Lighthouse Authorities (IALA) buoyage system, where red buoys indicate a safe channel for vessels to navigate. When a mariner sees a red buoy, it signifies that the hazard or obstruction lies to the right when traveling in the conventional upstream or seaward direction.

In this context, a red buoy indicates a navigational aid that warns of a submerged hazard or wreck, meaning vessels should keep that buoy on the starboard side as they navigate through the water. This color coding is essential for safe maritime navigation, helping to prevent accidents by clearly delineating areas that should be avoided.

The other colors mentioned serve different purposes in navigation. Green buoys usually mark the port side of a channel when returning from sea, while yellow is often used for special purpose buoys, such as marking pipelines or other obstructions. White buoys are generally utilized for delineating areas, like swimming zones, rather than for marking hazards that must be avoided.