Hornblower: The Examination for Lieutenant

The question given at Hornblower's Lieutenant examination, that of what to do in response to a "full a-back", relates to the sails of a ship suddenly flattening against the mast due to a change in wind. The correct answer (which Hornblower clearly does not know) is to put the helm over, haul up the mainstay and spanker sails, and then shift the helm in the opposite direction in order to fill the after-sails with wind in order to regain headway. Once the wind has been recovered, the ship should then brace up the sails and bring the ship's course directly in front of the wind. The maneuver to regain wind after a fall a-back is known as "chapelling", or "Chapel Ship", and would have been something which Hornblower absolutely should have known.

During the examination, Captain Foster describes a situation "with Dover bearing north two miles" and a "nor'easterly wind" that "veers four points". That would put the wind at east, but Hornblower is told that he would have Dover under his lee, whereas he would, at worst, have Folkestone under his lee and that eight miles off. Unless the wind were to veer a further twelve points at gale force, the tide would never put a dismasted vessel anywhere near Dover.

Followed by Hornblower: The Duchess and the Devil (1999)