This picture was taken abaft the funnel on an early steamship. Notice that the ventilator cowls on either side of the funnel are directed towards the stern of the vessel. A cowl is a usually hood-shaped covering used to increase the draft of a Chimney and prevent back flow The stern is the rear or aft part of a Ship or Boat, technically defined as the area built up over the Sternpost, extending upwards from the Counter

Abaft is a nautical expression indicating a point that is behind a given part of a boat or ship. This is a glossary of nautical terms; some remain current many date from the 17th-19th century A boat is a Watercraft of modest size designed to float or plane on water and provide transport over it A ship /ʃɪp/ is a large vessel that floats on water Ships are generally distinguished from Boats based on size For example, "abaft the funnel" means behind the ship's funnel (chimney). A chimney is a system for venting hot Flue gases or Smoke from a Boiler, Stove, Furnace or Fireplace to the outside (If not qualified, abaft means "behind the mid-point of a ship or group of ships". )

Note that unqualified or in the "abaft the beam" form, abaft does not necessarily refer to a point actually on the ship; it may refer to a point some significant distance away.