Unique Maritime Group Adds the Kongsberg cNODE family of transponders to its Rental fleet. Unique Maritime Group has announced the introduction of the Kongsberg cNODE family of transponders to their rental pool inventory. The cNODE transponders are for underwater acoustic positioning and data link that can use both the traditional frequency shift (FSK) modulation technique and the new Cymbal acoustic protocol which utilizes wideband Direct Sequence Spread Spectrum (DSSS) signals.