You might be surprised. Take a look at the following stats, and you'll see that except for one British depth charge (Mk X**) none of them could even reach 200 meters.
http://www.navweaps.com/Weapons/WAMBR_ASW.htm
This page will show that the US didn't have a depth charge that would go any deeper in service until a year after the war was over.
http://www.navweaps.com/Weapons/WAMUS_ASW.htm
They shouldn't go deeper, they should be shallower!