Aww, i wish my skimmer missions had a Corvette to shoot down.
I really really need to get around to shooting the engines off an NPC over a planet. I must know if it's hilarious or not .. lol
OP, like others said, look for temporary POIs within about a 100km range of the target.
Fly above 1.5km, zoom your scanner out, and look for blue circles on the radar.
Once you find one, fly to its edge, and drop down to about 100m altitude, facing the opposite side of the blue circle. (Blue circle with disappear below 1.5km)
Then fly straight to the other side, looking for anything out of the ordinary, like black objects that don't match the rocks.
Then land near it.

Most stuff spawns in the centre of the POI circle, so it's easy to find from the air.
If in doubt, fly back up to 1.5km and check your position. Or land and use your SRV to find the POI instead.
Skimmers at these will be mission targets, but are also usually wanted.
CMDR Cosmic Spacehead