Well this breaks every rule in "Good submarine battle tactics 101" but get a shooting solution on the convoy (not the ships the whole f-ing convoy) outside or at the edge of N-14 range. Run in under the layer, fire two salvos of fish (cut the wires on the 1st salvo and reload) and aim for the center of the convoy (where the "meat" is at.) Then run like hell. Repeat as needed.
