Moving skimmers are very difficult to hit squarely because they are more agile than other vehicles, and most shots are more likely to 'wing' them instead. To take account of this, any hits that would penetrate a skimmer that moved more than 6" in its Movement phase count as glancing hits instead. In order to qualify as moving more than 6", the skimmer must end its move more than 6" from where it started.
Players may not claim their skimmers are 'circling' or moving 4" one way and 3" back. Skimmers are dependent on speed to make the enemy miss, and adequate velocity cannot be attained while circling. If Immobilised while moving 6" or less the skimmer lands in its current position.