A bifurcating cyclical-ignition pulse was a pulse that enabled a lightsaber to activate underwater with the help of two crystals. Kit Fisto had one in his lightsaber. He would later record in a Jedi Holocron an explanation of how the pulse worked, and instructions on how to modify lightsabers to add the feature. The ancient lightsaber that Anja Gallandro had bought and formerly owned was waterproof, so was Cilghal's. Luke Skywalker would discover that Anakin Skywalker's lightsaber was waterproof. Ahsoka Tano's lightsaber and shoto were both able to function underwater. By 24 ABY, Luke's Jedi Praxeum students had already created lightsabers with the pulse as part of their regular design, rather than as an optional choice.
- Young Jedi Knights: Crisis at Crystal Reef (First appearance)