A seat, usually made of canvas, used to hoist a person up the mast.
A seat, usually canvas, used to raise a sailor up a mast.
A chair, traditionally made from a plank and rope, used to hoist workers aloft to maintain the rigging.
A bosun's chair is a device used to suspend a person from a rope in order to perform work aloft. It is distinguished from a climbing harness by the inclusion of a more or less rigid seat, providing more comfort than even the best-padded straps for long-term use. In exchange, the bosun's chair does not allow the freedom of movement necessary for climbing, and the occupant is generally hoisted or lowered into place using the rope alone.