Humminbird 1157c GPS Combo
Humminbird's 1157c GPS Combo uses a dual beam plus sonar signal for through hull broadcasting. The transducer emits at 200 or 83 kHz on the dual beam system, assuring you receive the valuable sonar information into the display screen and unit in the boat. Depth range for the shoot through hull transmission is 1,500 feet at the 200- or 83-kHz rates, or 3,000 feet with the optional 200-, 50- kHz transducer for deepwater use.
Humminbird 1197c SI Combo
The next in the 1100 series line by Humminbird with hull transmission capabilities is the 1197c SI Combo. This unit emits two different signals, one at 200 kHz and one at 83 kHz, and sends the signals back to the display via hull through broadcasts. The unit's depth range is up to 1,500 feet, or if the add-on is used, to 3,000 feet at 200 kHz or 50kHz. Side imaging is broadcast at 455 kHz and 800 kHz, providing 180 degrees of side imaging up to 150 feet. Signals for side imaging are broadcast back to the unit via hull signals.
Humminbird 958c Combo
The Humminbird 900 series uses the same hull frequencies as the 1100 series, but uses a smaller display screen and receiving unit. The unit uses sonar signals at 200 and 83 kHz to 1,500 feet. Like the 1100 series, options for extra signal strength are available through add-on transducers to a dual 200- and 50-kHz broadcast for depth range to 3,000 feet.
Article Written By Eric Cedric
A former Alaskan of 20 years, Eric Cedric now resides in California. He's published in "Outside" and "Backpacker" and has written a book on life in small-town Alaska, "North by Southeast." Cedric was a professional mountain guide and backcountry expedition leader for 18 years. He worked in Russia, Iceland, Greece, Turkey and Belize. Cedric attended Syracuse University and is a private pilot.