[Nisgeis]

Did Silent Service have a random campaign layer, or was it scripted? If you have a random encounter, you can decide at any point to drop out of TC and place a contact at the very edge of visible range.

If you have a scripted campaign, you have to continuously check whether any of the scripted traffic is within range of your sub's sensors at any given moment. The way this is done in SH4 is to take a slice of time, advance your sub x distance and see if there is any shipping in that new area within range. If you have a very fast processor, or low TC, then you can take very small slices of time and the sub will move only a short way per time, but if you are lagging (TC become jerky) then that means that your PC is having trouble and is having to take only one sample per update, so at say 4096 x TC at 14 knots, the the boat will move however far 14 knots over 4096 seconds is - 13 miles? If the CPU isn't fast enough to break that distance up into small chunks, then it has to jump the sub from the start to the end and if you are in range of a ship, you could end up 13 miles closer to it. At very high TC and severe TC lag you could hop from a point in front of a ship to a point well beyond it and your crew never see it.

If you 'back up' to a non stuttery TC level, you shouldn't get many problems.

At least, I think that's how it works. I could be wrong though. Probably am.