Note that if you have more than 12K men in transports in a sea zone, you take attrition while they're onboard.
I.e., if you have two separate fleets in the same sea zone and the total number of troops in those two fleets >12K, or just 1 fleet (or however many) w/the total # of troops >12K, you take attrition.
But if you manage your fleets carefully, you can avoid this. Probably not something you want to do as a beginner, as staggering your transports out like that is an invitation for disaster unless you've already dealt with enemy ships of the line and have sea dominance, but something to keep in mind.
Hmm, Wiki says 6000 men without attrition (http://www.paradoxian.org/eu3wiki/Mi...aval_Transport), but I have just checked, and I can put 8000 men without attrition on a fleet, and 12000 men in the same Sea region (without leader bonus) gives attrition.
Originally Posted by _Isladar_