How did it know??

[immortal44]

First patrol, came across a destroyer a good way away. Set an intercept course, stayed out of 2km (was night). By the time it came within 2km I was submerged and stationary, so it shouldn't have been able to see or hear me. Only popped the scope up a couple of times. Had everything nicely lined up and the damn thing changed course and came in my direction with floodlights scanning either side of itself. Started pinging me but I haven't read about how to get away (didn't expect to go after a destroyer first patrol) so first career was over pretty quickly

Earlier on I spent maybe an hour or more setting up a target only to ID it as a neutral ship a few minutes before I would have sent it to the bottom