When Carl Lowrance introduced the portable little green box depth finder with the rotating dial in 1957, it stunned the fishing world. By standards of today, it was not very good, not very accurate and gave only minimal information on fish and bottom structure. But it was better than anything else around, which at the time was nothing.
Since then, Lowrance has bought additional electronics companies and now makes many products for commercial and recreational fishermen and sailboaters. In the process they also picked up a few competitors that offer the same type of fishing units for the same purposes, with all of these companies having improved beyond the imagination of fishermen of 57 years ago.
Today it is possible to save data on cards similar to those used by photographers. That way, you can make and save your maps of each fishing trip or of best days and optimal opportunities. It is also possible to get features including connections with GPS units to pinpoint the hot fishing spots and get you back to the same bottom structure anytime you wish.
You can save the course taken for the day, reverse course to find your way home and make your own maps for future fishing fun. The latest hot thing for the best units is the 3-D system which gives you a photograph-like image of what you are looking at on the bottom. It is no longer a lump – it is a rock, sunken boat, abandoned car or old pier, and very identifiable.
And while the basics of all units and brands are the same, there are big differences between those units for freshwater vs. saltwater.
Let’s say that you fish freshwater rivers that range from very shallow to 50 feet in depth. For this, you are not going to want the narrow cone units best for deeper saltwater fishing.
As an outdoor photographer, I think of these cone angles as similar to the difference between wide angle and telephoto lenses. Some units, mostly for saltwater or very deep freshwater, give you a cone angle of about 12 degrees. That is narrow, but excellent for deep water.
For most freshwater fishing of lakes and rivers, you want a wider angle – wider cone – to cover more area and show more fishing possibilities.
For this, choose a unit with a 20 to 60 degree cone angle to show a lot without losing detail or losing the ability to pinpoint casting or trolling possibilities.
You can get the best unit for your purposes only by doing your homework. This means talking to dealers, going to specific brand web sites, visiting Internet chat rooms and fishing forums, and talking to friends and other fishermen about their joys and miseries with particular brands, units, depthfinder series, basics and accessories. That’s all valuable information that can only help you make the best possible choice.
Bought right and fished right, these units are invaluable sets of additional eyes – under the water and looking for the lunkers.