From: Citrus Heights, CA
100% will increase Fatigue in a major way. And I think fatigue has a deleterious effect on morale.
I believe that you accrue more ops losses below 6000' and I think that fatigue also raises more running ops under 6000', but I am not sure. As a general rule, I don't go below 6000'.
Welcome to NA. Numbskulls Annonymous. I have noted that whenever I fire up AE, that the Morale of my troops lowers, casulties soar. Not only that, but this game is so detailed that it has a sound effect of whining whenever I play.
ASW ops at 6000ft will rarely launch a weapon. That's a nautical mile up, moving, looking down for a vessel painted the same color as sea water with a beam of 27 feet. If you're lucky you might see a hint of a wake.
Look around on-line for photos of what ships look like from a mile up.
There's no consensus for what the optimal ASW altitude is, except it's lower than 6000 feet.
I figure I am not going to get many hits. I have been hoping to increase the DL of subs in the area enough that successful attacks are lowered....and because I play the AI, I am hoping to not break the game too badly. I also try to keep my Ops losses low. Still early in my war and I haven't got the pools of Aircraft I want.
That, and I am a numbskull.