When entering from sea, what type of buoy should be left to port?

When entering from the sea, the convention followed in navigational rules is to leave odd-numbered buoys to port. This practice is part of the IALA (International Association of Lighthouse Authorities) buoyage system, which provides a standardized way for mariners to navigate using buoys marking channels, hazards, or safe areas. The odd-numbered buoys are typically used to indicate the starboard side of the channel when you are heading upstream, and thus, the standard is to keep them to the left (port side) when entering a harbor or a channel from the open sea.

This buoyage system helps maintain consistency in markings, ensuring that mariners can easily recognize their position and the layout of the navigable waters. Familiarity with which buoys to leave to port and starboard is crucial for safe navigation and avoiding hazards in the waterway.