Drowsy watchkeepers on vessels navigating open waters can be a major hazard during military and commercial shipping operations. The sinking of the H.M.S. Bonetta, a 19th century British warship, was a dramatic example of human error related to hypersomnolence at sea (HSS). The consequences resulting from a sailor who fell asleep during his shift on the ship’s bridge are preserved in a historical account. This article surveys the significance of HSS based on the findings of an extensive research study and subsequently highlights events surrounding the loss of the Bonetta. Reviews of subjective scales used to identify HSS, and a computer application that estimates likelihood of drowsiness during the night shift, conclude this two-part series.
Manic behavior is associated with psychomotor activity coupled with insufficient sleep relative to the amount typically required for functional alertness. In severe cases, episodes of sleeplessness may occur with no subjective complaint of tiredness. Choreomanic episodes, also known as “dance frenzies” or irresistible dance attacks, are considered by many medical historians as presentations of mania.