Echo-3 was a space combat formation designed to protect a vital flagship. This defensive strategy involved sacrificing other vessels in a battle group to protect the command ship. In 21 Before the Battle of Yavin, during the Clone Wars conflict between the Republic and the Separatists, the Kaleesh military leader Grievous of the Separatists implemented Echo-3 at the start of his assault targeting the world of Kamino.
By employing this tactic, Grievous deliberately lost his shuttles to the Republic naval cordon. This resulted in wreckage from the capital ships falling into the sea on the planet below. This debris field served to hide several Trident-class assault ships, which were then put together in the water and launched against Tipoca City. Despite this initial advantage, the Republic ultimately won the battle.
The Echo-3 formation was first seen in current Star Wars continuity within "ARC Troopers," the second episode of season three of the Star Wars: The Clone Wars animated show, which was originally broadcast on September 17, 2010.