Wandering the aisles at the annual ICAST show last month looking at next year's fishing equipment, I realized that the convention is a window into the future in more ways than one. I'd heard about the new fish finders Lowrance was going to introduce, but their significance didn't really hit me until I saw them running in the company's booth.

There they were, relatively inexpensive black-and-white and monochrome color units showing a downscan view in detail amazingly close to that of the company's flagship HDS units. Here, for all practical purposes, were slightly smaller and much less expensive fish finders showing rocks that looked like rocks, trees that looked like trees, weeds that, well you get the picture.

The units show things in their actual shapes, not as the rounded blobs, lines and arches shown by traditional down-looking sonar units that we have to learn to interpret.

Considering these units as an evolutionary step requires a look back at the history of recreational sonar. Flashers came first, and we had to learn how to make sense out of the flickering lights dancing on their circular displays.

Flashers show a bright, stationary flash at the 12 o'clock position that marks the water's surface and tells you the unit is in calibration. They show another constant flash on the circular depth scale next to the number marking the bottom depth. Smaller flashes between these surface and bottom markers tend to come and go, change intensity and move up and down as they mark weeds, fish and other suspended objects.

All of these flashes are generated by a bright bulb mounted on a spinning turntable behind the display during each revolution of the turntable. You have to form a mental picture of what's going on under your boat from the flashes generated during consecutive revolutions of the turntable. You have to learn what it means when a flash appears, disappears, moves shallower or deeper on the depth scale or changes intensity. Is that a hard or soft bottom? Are those fish, baitfish, weeds, brush or submerged trees?

Combination flasher/paper chart recorders were the next evolutionary step. They removed the need for you to form a "screen history" of consecutive flashes in your head by printing a record of them on chart paper. Each time the unit showed a flash on its round scale, a stylus mounted on the back of the turntable burned a black spot on the scrolling paper. These units printed a curved reading on the chart because they were printed by a stylus on the back of the spinning round turntable.

Many found the curved chart images hard to read, and they were quickly replaced by straight-line paper chart recorders that printed with a belt-mounted stylus.

LCDs soon replaced paper charts, and provided even more capability without the hassle of paper changing, the need to clean carbon dust out of the case and the "electric train" sound and smell of a paper chart recorder.

The step from flasher to graphs marked a huge decrease in the time it took to learn to interpret a sonar display. Two of the best bass fishermen and electronics masters I know, twin brothers Billy and Bobby Murray, once told me that it took the average fisherman years to learn to use a flasher well enough to really understand what they were seeing, while it only took months with a graph unit.

Graph units let them teach an aspiring sonar user the basics in an afternoon, but it still takes a while longer for a student to differentiate between weeds and brush, rocks and stumps and to spot submerged timber.

Replacing the shades of gray on early LCD screens with the multicolor LCD screens that came next was an evolutionary step that helped considerably. They displayed different echo strengths in different colors rather than shades of gray, and most of us can tell blue from green at a glance while we might have to squint and stare a bit to tell gray level 10 from gray level 11.

Humminbird took the next step with the introduction of Side Imaging. Suddenly, we saw the bottom and structure off both sides of our boats in near-photographic detail. Interpreting blobs on the screen with educated guesses based on experience went right out the window. Shortly thereafter, Lowrance introduced StructureScan with similar side-looking abilities but also with DownScan, a down-looking component that shows what is directly under the boat in the same high detail. Humminbird then came out with a similar Down Imaging feature.

When next year's new sonar products hit the shelves, the Lowrance line will include Mark-5X DownScan Imaging fishfinders with five-inch 480 x 480 pixel Film SuperTwist black-and-white displays ($299 permanent mount/$349 portable). Step-up Elite-5X fishfinders ($549) will have color screens in the same resolution. These units are DownScan only, and will not offer an optional traditional down-looking sonar view like the bigger HDS units with the StructureScan option can show.

And, in this case, color means you can pick the monochrome color scheme that provides the best visibility for your ambient light conditions. They operate at 455 kHz for better depth penetration or at 800 kHz for better target separation and detail.

Elite fishfinder/chartplotter models with built-in 16-channel WAAS GPS antenna/receivers (external antennas also optional) will include the Elite-5 DSI ($649) with built-in basemap and the Elite-5 DSI Gold ($719) that ships with a special-issue Navionics Gold chart card. Both units have a waterproof micro SD card slot and can use LakeMaster, Fishing Hot Spots, Pro USA and Navionics Gold or HotMaps Premium chart cards.

So, about next January, we will have relatively inexpensive down-looking sonar units that require a learning curve of about one afternoon. The automatic modes that adjust the new photo-like screen pictures on side- and down-looking units from both Humminbird and Lowrance do a better job than most of us could do manually.

There is still about an afternoon's worth of tweaking that can be tried, but most of it consists of finding the color we can see best and locating rocks, stumps, weeds, trees and brush to look at so we can see for ourselves that they look exactly like we'd expect them to.

This leaves seeing fish as the only potential problem. These units examine a thin slice of water with each sounding instead of the traditional cone-shaped area, and fish don't stay in the slice long enough to be displayed as the arches we have come to expect. Instead, they can look like dots or elongated dots sort of like grains of rice. They are more pronounced in shallower water (up to 20-30 feet) and can even be connected to streaks, but in deeper water (50-60 feet or more) they can be lost in structure and easily missed even over an open bottom.

The new Lowrance units will include a Fish I.D. feature that might be useful to help you figure out what fish look like. But, unless it represents a breakthrough, these features are easily fooled and you'll want to learn to spot those dots with the fish symbols turned off.

For more information on the newest Humminbird and Lowrance sonar and navigation systems visit humminbird.com or lowrance.com.