What does a red buoy under the inland rules mean?

Under the Inland Navigation Rules, a red buoy typically indicates the location of a safe water mark or a channel marker. It is part of the IALA (International Association of Lighthouse Authorities) system, where red buoys are used to indicate the port side of a channel when entering from the sea. In inland waters, red buoys also serve to mark navigational hazards or indicate the edge of a channel. Boaters are expected to keep these buoys on their port (left) side when navigating upstream.