The Son'a battle cruiser was a type of large warship utilized by the Son'a. These vessels were armed with photon torpedoes and isolytic bursts, a variety of subspace weapon banned by the Second Khitomer Accords. Two of them outmatched a Federation Sovereign-class starship.
In 2375, two Son'a battle cruisers escorted the Son'a collector through the Briar Patch to the Ba'ku planet. They were later dispatched by Ahdar Ru'afo to prevent the USS Enterprise from leaving the Briar Patch and alerting the Federation Council to the Son'a's plans. Through the Enterprise's use of the "Riker Maneuver", one cruiser was destroyed and the other left on fire, requesting assistance. (Star Trek: Insurrection)