How do I shadow and time compress to night-time?

[yankee-V]

Assuming you are aft of the convoy and they are moving away, you really need to do what is called an "end-around".

Use your Watch Officer on the bridge to keep reporting the convoy bearing and range. Keep the range out to the limit, 6,000+ meters in good daylight weather, 3,500 meters at night.

After you establish the convoy course and approximate the speed, place yourself on a 45 degree track away from the convoy track until you are out on their flank but still in contact.

You will need to adjust your speed and course to stay in touch with them as they move forward and you move away. Once you have them on a relative bearing of about 90 degrees off your bow, turn back parallel to their track.

This should be the sequence where you can use the hightest TC to "pass" them at high speed on a parallel course. Once you have them at about 140 degrees off you bow, its time to start turning in maybe 35 degrees towards their track. Work your way close to their track, but still ahead of them before submerging (in daylight) or slowing to a crawl as youy near them (at night).

If you can stay in touch visually that's best. I have a hard time getting on the prefect track angle after losing sight and relying on hydrophone contact.