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).
| 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% |
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).
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).
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% |
