What does a red lighted buoy with a number 6 on it mean?

A red lighted buoy with a number 6 typically indicates a channel marker in maritime navigation. It signifies the port (left) side of the channel when entering from the sea, following the IALA (International Association of Lighthouse Authorities) buoyage system. The number 6 helps mariners identify their position relative to navigational charts. These buoys are essential for safe passage and navigation in coastal and inland waterways.