That was a huge jump from a few years earlier when anglers figured out bottom contour by looking at the bank, dropping lines with weights on them or by trolling and bumping the bottom. Those ways worked, that is how Linda caught her eight pound ten ounce bass in 1971. We learned about a long point by trolling Hellbenders over it, and that is where she caught the big bass.
A few years later I bought a Garcia paper graph. This curved line graph marked on paper with a wire that actually burned off a coating on the paper when electric current passed through it. The current came from the spinning orange light on the dial just like on the Lowrance.
That graph really helped me visualize the bottom and what the structure looked like. On my next boat I got a Lowrance paper graph. It printed a straight line reproduction of the bottom and everything between you and the bottom. It clarified even more what was below my boat and it and the next model I bought for my third boat probably taught me more than any other depth finder I ever had.
The paper for those graphs was expensive and hard to change, and the wire stylus burned up fairly often. But they were the top of the line depth finders at that time, in the early 1980s. At about the same time Liquid Crystal Display (LCD) depth finders started showing up. They put on a video screen the same kind of information my paper graph showed, without the hassle. But they were not nearly as accurate as the paper graph.
Now color graphs are available that will show a tiny baitfish swimming 30 feet below your boat. Every stump, rock and ditch on the bottom looks as clear as if you were looking at it directly. They are easy to use and almost all new bass boats have a color or black and white graph that is almost as good as my old paper graphs.
My current boat has a combination LCD graph and Global Positioning Satellite (GPS) on the same screen. The GPS system was developed by the military and is currently used by huge numbers of hunters and fishermen. They are also standard equipment in many new cars. The unit picks up signals from orbiting satellites and gives you your exact coordinates based on latitude and longitude.
I got my first hand held unit in 1997 and it was very basic, but amazing. I could put in a mark called a waypoint and it would remember it. If I marked a deer stand I could follow my trail back to it. If I marked an underwater brush pile I could find it every time I went fishing.
The newer units can save your trail, something that is great if you are trying to make a run in your boat in the fog. You an avoid the bank by following it. Unfortunately, it will not show you other boats.
My newest hand held unit cost me less than $200 and comes with a pre-loaded map in it. Every lake I have fished in the US has been on it, even some small 300 acre lakes in Wisconsin and Iowa. They were not perfectly accurate, but they are amazingly good for such an inexpensive unit. The one on my boat shows more detail but it costs a good bit more.
My trip to Antarctica last January proved to me the unbelievable amount of information those hand held units can hold. It showed the tip of South America, locating small towns I had never heard of before. But most amazing of all, as we approached the Antarctic peninsula, my little $200 hand held Lowrance GPS showed the islands and mainland there. I could not believe it.
Some folks think this technology is bad for fishing and hunting, making it too easy to find things. Maybe so, but I will continue to use it. It not only helps me find spots to fish, it guarantees I will not get lost in the woods or on a lake!