I used this and works great. I turn off the breaker when off of the water. It is a clean look and no need for a separate switch with an inline fuse.Bussman_187_30A.jpg
You can tap the circuit board (buss strip) in the boat, along the transom upper right, and BCB parts will sell you the Carling switch to install on a switch board. Ask for Richard on the part.
That “black power distribution bar” is a ground bar… very prone to corrosion and first place to look at when you get low voltage issues. Second place for low voltage issues is with the circuit breakers. There are in line fuses on various components. Not easy to find or get to in the garage let alone on the water. I took some time and rewired mine to a fuse panel when I rewired a separate power line for the added electronics. Took a while but now its easy to add a component or change a blown fuse.Practice Angling CPRCatchPictureRelease2010 PIV 200SHO