Dropping depth charges continuously until you know the sub has been sunk is foolish. You only have 75 charges for the entire voyage. Wasting them may leave you unarmed later when you need them. As well, if you continuously drop the charges your ASDIC operator cannot listen for any new contacts. The explosions make the ASDIC useless. After all your charges explode off there is no clear evidence of a hit and you return to your escort station feeling foolish over wasting your weapons. The escort commander is extremely angry with your captain's actions and tells him to expect a new posting - on shore!