Mount the Transducer
There are a few places you can mount the transducer, inside the hull, over the side, or thru the scupper. Now there may be some other locations but these are the three most popular locations. Deciding where to mount your transducer depends on a few different factors. What kind of fishing do you like to do, deep lakes, shallow or small water, blue water, river, etc. Basically will your transducer be exposed to damage. Next you want to consider the type of fish finder you have. Most standard fish finders will work well in any location you choose. DSI or down scan imaging fish finders, like the one I'm installing today, may not work well when inside the hull. While some people may have luck with this type of installation, Lowrance specifically states in their mounting instructions that thru hull installations are not recommended because it significantly degrades the DSI performance.Because my fish finder is a DSI I'm going to mount thru a scupper hole for direct access to the water and hopefully best results. One note before I continue, there are plenty of discussions about turbulent water around the scuppers causing less than desired performance out of your transducer. I made the decision to ignore these discussions after I came across a scupper transducer mount made by Lowrance.
With all the above said, here's how I did mine. I started with a threaded plastic tube from the plumbing department of Lowes. Cost about $1.50. I added a cap to help retain the pipe from falling through. I used a 1" diameter pipe but the size might be different depending on what will fit through your scupper. Measure your scupper and head to Lowes or Home Depot.
