I just bought a helix 7 chirp gen 2. I put it on last weekend and used it for a few hours .... so far so good . Bright screen easy to use buttons . It won't operate under 10 volts so make sure your batteries have enough juice to run everything or run the helix to its own power source . My navionics chip was back ordered but should be here tomorrow , so after this weekend I should have a better review . So far I'm happy... check out boatersland. Com , best prices I could find . $454.00 for the 7. Good luck