The altitude at LAN may be observed by starting several minutes in advance and continuing until a maximum altitude occurs. This procedure should not be used __________.

Correct Answer: Option A — on a fast vessel on northerly or southerly headings

According to Bowditch, a fast vessel on northerly or southerly headings experiences rapid changes in latitude invalidating the constant-latitude assumption during Local Apparent Noon altitude runs, causing significant timing and position errors due to the vessel's own motion altering the observed time of maximum altitude.