Selecting Speeds

Although cranking settings to maximum is no longer needed in modern sonars, a couple of parameters are best taken to the limit—that is, to a 100-percent setting. Ping speed and chart speed both affect how fast impulses are dispatched and returned to the sonar unit. Ping has to do with the rate at which the sonar’s signal is sent out, returned, and interpreted by the unit’s processors. Furthermore, keeping ping at max rather than frequently adjusting it is going to yield a semblance of consistency in what you’re seeing—all the better for your own interpretation.

Setting chart speed at max, which influences how fast the picture moves or scrolls across the screen, accomplishes something similar. At 100 percent, the readout shows what’s being displayed at the fastest rate possible for the best possible real-time viewing, with better fish arches in the shape of elongated, upside-down smiles rather than more compact, inverted V’s.

Side-Imaging Sonar

In 2005, Humminbird introduced a new type of sonar. Their high-end units have Side-Imaging (SI) sonar color imagery plus GPS map navigation features. At roughly $2,000, the Humminbird 987c SI is about the most expensive sonar and GPS unit available. But experienced anglers have found the SI to be a better searching tool than standard units.

Buyers gain a new search capability that simplifies the process of finding cover and structure likely to hold fish. SI allows an angler to make passes down a shoreline or around important structures and mark spots as waypoints. The angler can then return to fish each waypoint to see if the spots are productive. Users more rapidly learn new waters and gain knowledge about underwater features they already fish.

One drawback is that fish returns are smaller and more difficult to identify in SI imagery compared to standard vertical sonars. Schools of small baitfish appear as murky clouds rather than dark blobs. Fish the size of crappies or yellow bass may appear as small white dots, and individual gamefish like bass aren’t much different from the returns created by stumps on bottom; but this is a cover-location tool, and effective use always has a learning curve.

Although gamefish and baitfish show as separate returns in SI imagery close to the boat, fish echoes farther to the side are mixed in with returns from the bottom and are more difficult to see. The clue that an SI return is a fish rather than a bottom or cover echo is a matching fish shadow farther away. Side imaging can help an angler locate and relocate moving schools of predator fish in relatively open water, but this is a bonus feature, not a primary benefit.

Beds of underwater vegetation are visible as marbled or bumpy bottom, but the soft edges of many submerged weedbeds may be indefinite. The prime benefit of SI is in definition of hard elements. Rockpiles and the deep edges of riprap are clear. Bridge construction and cover near pilings are revealed. Laydowns and underwater brush seen as blobs on bottom with vertical sonars become distinct logs and trees with defined branches. The clarity of various images recorded with the SI can be seen on the Humminbird website (humminbird.com). The increased fishing capability created by such detail is much like having photographs of exposed cover in a reservoir or lake.