Good lord! What did you do?
I'm glad you asked.
My veteran ships were taking a pounding from the Drengin, so I fleeted them with empty huge hulls hoping to sacrifice the empty hulls and keep the veterans. The opposite happened and the empty hulls got incredible experience during the scuffle while the veterans died. Since I allowed myself two warships in the game, I upgraded two of the empty hulls to warships to replace their fallen comrades and decommissioned the other survivors.
Evidently, the experience was given based on their attack and defense values (0) + the hull hit points against the defending fleets (700+ Att, 700+ def + hull values)
I assume that the max experience level is 102, seeing that the number has come up on a few occasions and my empty hulls didn't breech that limit.
It would be a quick way of getting uber survivors for fights against superior enemies.
And now, the playing field has been leveled.