ROUTINE OF LIVING ON U.S.S. DOGFISH UNDER WAY 



333 



and 20 o'clock. In other words, over 90 

 percent of the entire personnel were up dur- 



The diurnal distribution of the sleep per- 

 iods for the different sections is shown in 



TABLE I 



Distribution of Sleep Periods, Estimates and Actual Mean 

 Durations of Sleep, Self-Ratings, and Preferences 



Percentage of Distribution of Men/Sleep/Dats on Sub- 

 marine 



Single long sleep periods per 24 hours 



Two equally divided sleep periods per 24 hours 



Two unequally divided sleep periods per 24 hours 



Three or more sleep periods per 24 hours 



Mean Duration of Sleep 



Sleep ashore, estimate in hours 



Sleep on submarine, estimate in hours 



Actual mean duration of sleep on submarine 



Self-Rating 



Highest alertness ashore: in the morning 



in the middle of the day 



in the evening 



late at night 



Fully alert after awakening, on submarine: at once 



in less than 15' 

 in 20' to 45'... 

 in 1 to 2 hours. 



Quality of sleep on submarine: better than ashore 



same as ashore 



poorer than ashore 



Preferences 



Group A, number of men for fixed watch schedules 



Group B, number of men for rotation of watch schedules. 



Number of Group A who prefer day duty 



prefer evening duty 



prefer night duty 



are indifferent to hours of duty . 



Number of Group B who prefer day dut}' 



prefer evening duty 



prefer night duty 



are indifferent to hour of duty. . 



Number of both groups who prefer day duty 



prefer evening duty 



prefer night duty 



are indifferent to hours of duty 



All 

 sections 



8.09 

 8.50 

 9.06 



18 



39 



14 



3 



9 

 21 

 30 

 14 



3 

 19 

 51 



44 

 30 



12 



5 



10 



17 



10 

 5 

 3 



12 



22 

 10 

 13 

 29 



ing the supper hours, while less than 35 

 percent were up between 2 and 6 o'clock. 



Table I. Very few men in the watch sec- 

 tions could satisfy their sleep requirements 



