Naval Attrition - Level 37

[unmerged(2073)]

This is something I can't follow. Having reached level 37 on naval technology I feel it's time to cut down on pirate activity and place fleets all over the map. After about a year, I find them suffering from attrition due to "Time at sea"

Any ideas why?

 

[unmerged(4433)]

Even level 37 simply just doesn't eliminate attrition completely. The info in the game is false. Maybe reaching the level was supposed to do that at some point of the development phase?

 

[unmerged(1095)]

Even in todays modern navies I would feel attrition after a year at sea. I guess those guys in their rickety ships felt it even more.