Just look at the pictures—obviously, this is a serious improvement in side imaging. How does Humminbird do it?
Khz (kilohertz, or frequency,) is one big part of the equation—the frequency of the beam transmitted by your unit will determine what you see and how well you see it. High frequencies put out short, fast sound waves that are sensitive to small items. Low frequencies put out long, less frequent sound waves which are less sensitive to small items but they’ll travel farther. Think of it like tossing something into a pond. A golf ball makes small, fast waves, which bounce back when they hit small items. That’s a high frequency wave. (Commonly 200-khz for fishfinders.) But if you threw a boulder into the same pond, it would generate much larger and less frequent waves. They’d roll right over small items without even noticing them, but those big waves would also continue on for longer distances. That’s a low frequency wave. (Commonly 50-khz for fishfinders.) Now consider the Humminbird’s side imaging beams: they’re incredibly high 455- and 800-khz beams, so they have awesome detail.
Another part of the equation is beam angle, expressed in degrees. Low degree angles are tight, more detailed beams. High degree angles are wide, less detailed beams. Think of beam angle like a flashlight: when the beam is tight, the flashlight is set to spotlight to illuminate a small area brightly. But when the beam is wide the flashlight is set to floodlight, spreading its power over a wider area. So, what beam angle does Humminbird SI use? One—about as focused as you can imagine—horizontally. But the beam is fan-shaped, with an 86-degree vertical angle. Essentially, it’s taking an MRI-like picture of what lays off to the sides of your boat.
Finally, the unit offers a surprising amount of power, pumping out 1,000-watts RMS. Combine high power, super-high frequency, and incredibly focused beams, and you get images that cover 50 to 75 times the area as traditional side-finders, with infinitely better detail. In fact, target separation is 2.5 inches.
When I used the 1197c, the techno-babble translated into the best side imaging I’ve ever seen, by a heckofa long shot. Try one of these units out, and you’ll agree.
Price: $2,200 to $2,800 depending on accessories/chartography added.
The Highs: This will blow your mind—it’s awesome!
The Lows: Only effective in water less than 150’ deep. Transducer installation is critical to performance and can get tricky.
Who Wants It: ME!!! (And anyone fishing bays, lakes and rivers under 150’ deep.)
Contact: www.humminbird.com
