The HELIX 12 CHIRP SI GPS is the top unit of the HELIX group. It’s the best unit from Humminbird for 2016, at least so far. It offers just about everything the other HELIX units have, including Side Imaging, Down Imaging, GPS, ContourXD maps, AutoChart etc. And on top of all these, it also features CHIRP sonar technology.
Technical Details and Specifications

    Screen: 12.1? diagonal, 65,000 color TFT, 1280H x 800V pixel resolution, 16:9 aspect ratio, with backlight
    Sonar: Broadband CHIRP, Dual Beam Plus, HD Side Imaging, HD Down Imaging
    Depth Capability:
        150 feet (45 m) for Side Imaging and Down Imaging
        1500 feet (457 m) on DualBeam Plus
    Frequency and Coverage:
        DualBeam Plus: 200 kHz / 20° and 83 kHz / 60°
        Down Imaging: 455 kHz / Narrow, Medium and Wide fan-shaped cone
        Side Imaging: 455 kHz / 86° (x2), and 800 kHz / 55°, 480 ft. side-to-side coverage
    Transducer: Transom XHS 9 HDSI 180 T
    Max. Power Output: 1,000 Watts (RMS)
    Power Input: 10-20 VDC
    GPS: Internal, Precision
    Maps: ContourXD (built-in)
    Routes, Waypoints, Tracks: 47; 2,500; 50 (20,000 points each)