Right... I very rarely use the fan shot myself. One time I did, was when I was zeroing up on a T2, and the DD in front of the convoy was zeroing in on ME (1000m astern, and pinging me). I knew I'd only get one shot, so I let everything rip at that T2, and dove deep. As luck would have it, the very first torp blew the T2 sky-high, and that wasted the other torps
but hey, T2's a good kill in any event.
