Hypersomnolence at Sea, Part I
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.
An international study composed of nearly a dozen European academic institutions and shipping industry representatives examined the effects of sleep loss on cognitive performance among maritime watchkeepers. The officer on watch oversees bridge operations of a vessel during the shift. Among the many responsibilities of the watchkeeper are mapping the ship’s position and maintaining course; managing radio communications; updating the ship’s log; and passing along information during the shift change.
Drowsy Versus Fatigued
Their report published in 2012 differentiates drowsiness, defined as the struggle to delay sleep onset because of working irregular hours during the night shift, from the more general experience of physical or mental fatigue caused by long daytime hours and demanding work responsibilities. According to the International Classification of Sleep Disorders, a circadian rhythm sleep disorder (CRSD) due to a chaotic work schedule can impair cognitive performance.
In the rest of this article from the Q3 2018 issue of A2Zzz, Reg Hackshaw, EdD, delves further into the history of the Bonetta.
This article is one of four designated CEC articles in this issue of A2Zzz. AAST members who read A2Zzz and claim their credits online by the deadline can earn 2.00 AAST Continuing Education Credits (CECs) per issue – for up to 8.00 AAST CECs per year. AAST CECs are accepted by the Board of Registered Polysomnographic Technologists (BRPT) and the American Board of Sleep Medicine (ABSM).
To earn AAST CECs, carefully read the four designated CEC articles and claim your credits online. You must go online to claim your credits by the deadline of Nov. 30, 2018.
After the successful completion of this educational activity, your certificates will be available in the My CEC Portal acknowledging the credits earned.