gsd-26-chirp-professional-sonar-moduleGarmin GSD 26 Digital Sonar The GSD 26 digital sonar ushers in the next evolution of sportfishing technology, providing unrivaled target separation at far greater depths than traditional sonar. Discover Spread Spectrum ClarityFor serious deep sea sportfishing, the GSD 26 takes high definition targeting to a whole new level. With a compatible transducer, its Spread Spectrum technology scans multiple frequencies at once, returning vast amounts of data