I would use some 1" pvc and make a pole to mount it on, use conduit straps to mount to the edge of the dock.
https://www.homedepot.com/p/Oatey-1-in-Copper-2-Hole-Pipe-Hanger-Strap-33518/303434709#overlaybattery box with a 50ah lithium and mount the black box to the top, store extra wire in battery box.
a small wagon (radio flyer type) to mount the graph, battery box and store the ducer when not used.
how I would do it anyway.