Okay, I can't find this guy. I'm on my first real mission, tracking my first real contact, and I can't find him. One minute he's here, the next minute he's there. I've been following him for hours and haven't caught site of him once. I only know roughly where he is by submerging and listening to the sonar.
You see, the trouble is that it's dark and raining, so the visibility must be really low. I guess I can just follow him until it stops raining. Or I run out of gas. But I thought I might see if you guys had any brilliant ideas.
By the way, check out my navigator's weather report. Pay careful attention to the part about percipitation.