A battle cruiser is a specifc variant of the Defender Class Starship that provides tactical support to Exploring Expeditions. The Permanent Saphire Defense Situation has the ships built under a custom design with upgraded armor and weapons systems. Although they may be crewed with personnel from any world, they operate specifically under Sapphirean Flag and Sumacian command and operational protocols, most commonly in support of Exploring Expeditions sponsored by the Free Worlds Alliance.

The PSDS makes it a point to give these ships names intended to threaten and intimidate adversaries. Known examples of the type include:

  • · Skullcrusher -- The ship to which Blade and Hardcandy Banks Toto transferred in Book 11 - Charlemagne. Skullcrusher was part of a seven-ship Exploring Expedition into the uncharted Carinae Quadrant.
  • · Doombringer
  • · Punisher
  • · Annihilator
  • · Mutilator
  • · Firestorm
  • · Deathblow
  • · Warhammer
  • · Widowmaker
  • · Hellfire