Ice Fishing Sonar Option on the Cheap
Any ice fisherman understands the value of being able to see underneath the ice, most often by means of an ice fishing sonar like the popular Vexilar or various Humminbird and Garmin units. While these pieces of equipment can be crucial to finding fish in the winter, the price tag can sometimes be hard to justify. There is, however, another way to get the same results with the gear you may already have.
The main object you will need to make your own ice fishing sonar is a simple digital graph. It doesn't have to be anything fancy. I used and old Lowrance X50 DS Fishfinder.
The next step is to find a small box or case to carry the unit in. It should be large enough to hold one or two batteries, the transducer, and the unit itself. Make sure it is also large enough to contain the excess transducer cords which can be bundled together and zip-tied. Another option is to use an even larger box to carry ice fishing tackle in it as well.
The batteries themselves can be just about any 12 volt battery. Batteries specifically for ice fishing sonars can be purchased for as little as $40, such as the Lipo Hobby Batteries that I used. It's a good idea to purchase an extra battery too, just encase. Generally batteries do not last nearly as long in cold temperatures as compared to warmer temperatures, so having a spare ready to go can save you time and frustration.
One of the trickier parts of this conversion is properly orienting the transducer in the hole so that it is pointing downwards and and doesn't change position. This can be done by attaching the transducer to a 1/2 inch wooden rod 8-12 inches in length. Zip-tie a piece of foam or pool noodle on the top section of the rod so that the rod floats in an upright position.
Now, rather than spending $70 to $150 on an "ice specific" transducer for your graph, let alone $400-$600 on an entire unit designated to ice fishing, you now have a graph that cost next to nothing. The conversion takes less than an hour and when you are done ice fishing, the graph can be easily re-installed back on the boat. Now for the fraction of the price you have a dual purpose fish finder for all seasons.