Use astern for precise nautical positioning: 'the lifeboat drifted astern', 'a vessel astern of us'. For position behind relative to another ship, use 'astern of': 'we were directly astern of the tanker'. It is more specific than 'behind' and clearly signals a maritime context.
| Incorrect | Correct |
| The engine room is astern. | The engine room is aft. |
| Keep aft of the other vessel. | Keep astern of the other vessel. |
Use astern for a vessel's backward movement: 'go astern', 'engines astern', 'full astern'. This is the command and reporting form used in navigation and engine orders. 'Full astern' means full reverse thrust.
| Incorrect | Correct |
| The captain ordered the engines into reverse. | The captain ordered the engines astern. |
| The vessel moved backwards from the dock. | The vessel moved astern from the dock. |
Astern covers both position ('the wreck lay astern of us') and movement ('engines astern'). For position within a vessel, aft is more common. For direction relative to another vessel or for engine orders, astern is the preferred term.
Astern and aft are related but not interchangeable. Aft is used for position within a vessel ('the aft deck'); astern is used for position relative to another vessel or for backward motion. Also note: ships go astern, not 'in reverse'.
From a- ('on, toward') and stern, the nautical term for the rear of a ship. Stern itself came into English in the early 13th century, probably from Old Norse stjórn ('steering, rudder'), related to stýra ('to steer'). The compound astern is first recorded in the 1620s in nautical texts.
What does astern mean?
Astern means at or toward the rear (stern) of a ship, or behind another vessel. It also means moving backward: 'the captain ordered full astern' means full reverse thrust.
What is the difference between astern and aft?
Both relate to the rear of a vessel. Aft describes position within the ship ('the aft cabin', 'go aft'). Astern describes position relative to another vessel ('a ship astern of us') or backward movement ('engines astern').
What does 'full astern' mean?
Full astern is a nautical engine order meaning maximum reverse thrust — propel the vessel backward at full power. It is used to stop the ship quickly or to move away from a berth.
What is the opposite of astern?
The opposite of astern is ahead (for direction or movement) or fore/forward (for position).
Where does the word astern come from?
Astern combines a- ('on, toward') with stern, from Old Norse stjórn ('steering'). The compound is first recorded in English nautical texts in the 1620s.