You're changing the wrong thing.
Get your original Basic.cfg (hope you backed up 1st!)
Now go to the section that starts [FATIGUE_COEF]
and change it to the below:
Those factors are how fast your crew fatigue in a 10 minute period. Lower figures = lower fatigue rate over time.
Changing FatigueStep to 0.05 for your seamen means it takes them 4 times as long to recover, as every 10 mins they only recover 5% of their endurance, instead of the 20% before.
The FatigueMax is where the Red ! marker appears. 30 means it appears at Endurance=-29, so don't bother with that it's too crude. If you really want zero fatigue in your game change all the Regular/Specific/BadWeather factors above to =zero.
If you don't like changing your crew every 80-120 minutes use churches figures in the [FATIGUE_COEF]
section above. They work very well. If you think that the crew recover fatigue too fast after their 8hr shift then reduce FatigueStep to somewhere you find comfortable.
The original subsim thread: http://subsim.com/phpBB/viewtopic.php?t=30783
Hope this helps