13 days ago - Ahskance - Direct link
Checked the Replay.
It looks like the Sub pinged another ship behind you which activated the homing on the 3 torps fired after.
Torps heading to first target (Sherman or Yoshino B):
After that, the sub tried to ping you, but missed.
If there was no active ping, the torps would not have risen to the surface at all. You can see they were fired below the surface so their being able to rise shows the ping was still active on the other ship.
The torps fired rose to the surface and tracked toward the active ping. You were in the way :(