This is one of the cheapest units of the new, 600 series, Hummingbird fish finders with Down Imaging. Although it does not have too many navigational options, the Humminbird 678c HD DI sure covers pretty much everything a fish finder should.
Like most units within the Humminbird 600 series, this one comes with a 5-inch diagonal screen, 640 x 480 pixel resolution. It’s a full color unit, with LED backlit screen, making the readings quite easy during night fishing.
Comes with Dual Beam Plus sonar, SwitchFire and High Definition Down Imaging technology. The DI beams can be operated at two frequencies: 455 kHz / 75° or 800 kHz / 45° for a more focused view, being able to scan depths up to 350ft. The transducer of the 678c HD DI also uses traditiona, 2D view with two narrower beams, of 16° / 455 kHz , or 25° / 200 kHz. The 2D, traditional imaging works for depths up to 600 ft. The standard transducer of this unit is the Transom XNT 9 DI T.
The 678c HD DI unit has a PTP power output of 4,000 Watts (500 Watts / RMS). It does not support any type of chartplotting, in other words, cannot be upgraded with any Lakemaster or Navionics mapping package. Also, does not have any built-in cartography, such as the 698ci HD SI Combo or 688ci HD Combo.
The box also contains the Quick Disconnect mounting system, but it can work with an in-Dash Mounting system as well. However, the second one is optional.