I dont use external camera so its impossible for me to check where DC's expload but when i was trying avaiod charges using ahead flank when destroyer was direct over me. DC's destroyed some things mainly in stern compartments (diesel and electric engines) so it seems to work for me.
But im not 100% sure because of lack of external camera.
Im using u-boat killer mod v1.02 (
http://www.subsim.com/radioroom/showthread.php?t=165886 ) witch have some modifications of DC's damage radius to feel how close explosion was (and to have some more realistic fun with destroyers).