A pair of foam-padded steel J hooks that screw into wall studs and hold up to 100 lb between them: a kayak, a SUP or a canoe on its side, off the garage floor.
Each hook stands 25 inches tall and reaches 15.25 inches from the wall, which is room for the hull of a recreational kayak on its edge. Set the pair about a third of the boat's length in from each end and the weight spreads across two studs.
Buy one pair for one boat, or the 2-pair and 4-pair packs to line a wall. The hardware and instructions come in the box, and the same J works for a surfboard, a snowboard or a ladder when the boats are on the water.
You will work overhead or at the top of a stud wall, so set the ladder on a level floor, face it and keep a hand on it while you drive the screws. Fasten the brackets into solid framing (a joist, a rafter or a stud), never into drywall alone, and read the instructions in the box first.