'round here, most use plastic tubs. You set up your BCD/Tank/Regs on land - then use the convenient fact that a BCD is a backpack, throw it on, grab your tub containing weights (or you can put them on too if you want), fins, mask, exposure protection etc & carry it on. Tub goes under your seat, sit down and remove your BC. I have a mesh bag and a small 5l dry bag sitting empty in the tub - once I am on board and my car is locked up, throw keys, wallet, phone etc in the dry bag. When I undress, dry clothes into the mesh bag, throw the dry bag in on top, and either stow high, or stow somewhere dry.
Once you are done for the day, all the wet stuff goes straight into the tub. mesh & dry bag goes in too (since they are now empty) - if you are lucky there will be a source of fresh water on the dock to do a hose down of the gear, and you can use your tub to soak everything whilst you crack open a few beers from the esky on the back seat of your car.