Symptoms of fatigue

Respondents were asked to identify as many different symptoms of fatigue based on a list provided. The most chosen symptoms appeared to be those that have been readily identified in the fatigue management/sleep literature, i.e. sleep-related (nodding off (71%)) and cognitive impairment symptoms (unable to concentrate (75%), mood swings/irritable and slow responses (both at 69%), and poor judgment (65%)). Least identified symptoms were those that tend to be manifestations or behavioural outcomes of a fatigue state, i.e. affected speech (32%), risk taking (37%), headaches (41%), and body aches and pains (42%)). Also, less than half of respondents (48%) identified symptoms relating to awareness of their own performance and memory issues. These identifiable behavioural symptoms appear to be areas that can be presented to seafarers in education and awareness material as they are symptoms of a fatigued state that they might be able to identify not only in themselves, but in their crew too (Table 5 and Figure 13).

Table 5: Symptoms of fatigue frequency count and percentages of total
Symptoms of fatigue Frequency Percentage
Unable to concentrate 767 75%
Headaches 422 41%
Mood swings/irritable 702 69%
Slow responses 703 69%
Poor judgment 666 65%
Taking unusual risks 383 37%
Difficulty remembering events or procedures 491 48%
Unaware of own poor performance 488 48%
Affected speech 323 32%
Body pain (e.g. muscles, joints) 429 42%
Nodding off 726 71%
Selected all 160 16%

Figure 13. Which of the following do you consider to be symptoms of fatigue (select all that apply)?
Figure 13. Which of the following do you consider to be symptoms of fatigue (select all that apply)?

Respondents were asked to state if they had experienced any fatigue symptoms either before or during their time at sea. 25% (252) stated that they rarely or never experience symptoms, nearly half of the respondents (48%, 496) stated sometimes, and 27% (276) stated they experienced fatigue very often or most of the time. This reiterates the importance of educational and awareness support to ensure they understand what they need to do to continue to operate their vessels safely (Figure 14).

Figure 14. Have you experienced any symptoms of fatigue immediately before or during your time at sea?
Figure 14. Have you experienced any symptoms of fatigue immediately before or during your time at sea?

Fatigue risk factors

Respondents were asked to identify as many factors from a list provided that they considered increased the risk of fatigue. As with the question on symptoms, most respondents chose those factors that are readily identifiable for increasing risk, i.e. long working hours (86%) and inadequate sleep (82%). Factors such as working at night (64%), poor weather conditions (65%), insufficient rest or break (67%) and inadequate crewing (49%) were also highly rated risk factors (Table 6 and Figure 15).

Table 6: Factors that increase the risk of fatigue frequency count and percentages of total
Factors that increase the risk of fatigue Frequency Percentage
Long working hours 831 86%
Poor weather conditions 623 65%
Inadequate sleep 788 82%
Poor diet 460 48%
Inadequate crewing 470 49%
Insufficient rest/break 643 67%
Working at night 619 64%
Other 114 12%

Figure 15. Which of the following do you consider to be factors that will increase the risk of fatigue (select all that apply)?
Figure 15. Which of the following do you consider to be factors that will increase the risk of fatigue (select all that apply)?