One of the issues when transiting an area with a mix of vessels, fishing, coast-wise, fast and slow deep sea vessels is missing a large vessel while concentrating on avoiding fishing vessels and the more difficult task of avoiding fishing gear.
With target trails set on true motion a large fast moving ship stands out on the screen from the smaller, slower (and often dead in the water) fishing vessels. The fishing vessels will have no or negligible trails. The big fast ships will have long, wide trails easily seen
Same is true moving in anchorage at night, with target trails on it’s much easier to pick out that one "anchored’ ship that is moving with all deck lights still on or the one giant moving with just running lights against the background shore lights.
In that scenario, or any time there’s a bunch of targets, I’ll also turn on the PI lines, on both sides of the display if the radar is so equipped, and set them parallel to the heading line with moderate-to-close spacing. That will give you a very quick way to sort out anything moving at an angle to you.
Handy going by or through the Rabbit Field, or any other place in the GOM and other oil fields. And, again, it is independent of the gyro and so really can’t ever lie to you should there be a gyro malfunction of some kind.
If you are meeting a lot of targets, like a stream of fishing vessels leaving or entering port, it can be helpful to set one EBL 10 degrees port and the other EBL 10 starboard. You’ll quickly see which targets Are a problem.
The predictor lines on the ECS are also very helpful.