Skater is a light scout/AA ship. They offer very high speed, and a large line of sight. Use them in the beginning of sea battles to harass your enemy’s early base structures, and block their constructors from expanding. Their AA turret is weak and won’t stand a chance against more advanced aircraft, but during the T1 stage they provide useful protection from EMP drones and gunships. Always include a bunch of them in your fleet.
They are hopeless in a matchup with any other ships, so only use them as a support/scouting force.
Skaters are a faster than their CORTEX counterpart (Herring).