6 or 7 gal bucket, ht padded seat, filled with expanding foam to hold a plano box and 7ah battery, swing arm mount for hb 175 graph. I let my friends use this when they come with me.
Tips: pvc fittings can be used as rod holders
use expandable foam inside to make custom compartments
remove the metal handle and replace with rope and a piece of rubber hose - more comfortable to carry
you can string a pair of ropes through the normal handle mounting holes and create backpack like straps (think a trapping basket)
slide a 5 gal bucket inside a 6 or 7 to bring more stuff with you