Aiming-off is aiming at a Line Feature deliberately to one side of the Target.
Reaching the Target directly could be difficult in poor visibility, and if it is missed, the walker would not know which direction to go in order to find it.
Aiming-Off is deliberately heading to reach a Line Feature some distance to the left (or right) of the Target.
When the Line Feature is reached the walker will know which direction to go along the Line Feature (i.e. Handrail the Line Feature) to reach the Target.
Examples of Aiming-Off might be:
Aiming for a Stream (Line Feature) to the west (left) of the Bothy (The Target).
Once the stream is reached the walker will know to head East (right) beside it (or Handrail the stream) to reach the Bothy (see above) or
Aiming for a Field Boundary Wall (Line Feature) to the South of a Trig Point (The Target).
As soon as the Field Boundary is reached the walker will know to head North beside it (or Handrail the Field Boundary Wall) to reach the Trig Point.