IMO, the best way to go about it is to run a pair of wires from the battery to one of these Amazon.com: Blue Sea Systems 5025 ST Blade Fuse Block - 6 Circuits with Negative Bus and Cover: Sports & Outdoors then feed each of your finders from the fuse block.

I used 10AWG marine wire on mine, but 12 would have been plenty. Fused the positive feed wire at the battery. And ran the positive through a 20A switch in the console so I can turn off power to all of my electronics when I'm done for the day. Cut the inline fuse holders out and installed the fuses in the block. Now all of my fuses are together under the console. I have 2 finders, my NMEA bus power, my LSS and my radio connected to the block.

It's possible the landscape wiring is tinned, I just don't know.