Abeam refers to a position directly opposite the midpoint of a boat's side, at a 90-degree angle to the vessel's keel or centerline. It indicates that an object, landmark, or wind is straight out to port or starboard, specifically at the widest part of the boat, often described as "at three or nine o'clock".

Key aspects of the term abeam include:
Location: It is used to describe the position of an object relative to the boat, such as "the buoy is now abeam".

Direction: It defines a perpendicular line extending from the boat's center to the sides.

Wind/Sailing: If the wind is "abeam," it is blowing directly into the side of the boat (also known as a reach).

Compared to other terms: It is distinct from abaft (further back) or ahead (forward).