I need to take some pics of mine. I have a porch/deck that wraps around 3 sides of my house. The house is on a hill with a walkout basement in the rear. I just used some scrap pressure treated deck lumber to make a couple of big U's on both the back and north side of the house under the deck. 2 uprights each end and a crossbar for the boats to sit on upside down. Sort of like the rack above but with end pieces. They are high up against the decking so in the back where we actually walk sometimes I can walk under the boats. I don't have a yak anymore but have 2 canoes at the moment. I can carry my tandem on the shoulder portage yoke and just slide it on the rack. The deck keeps most of the sun and weather off the boats and the house protects them from the wind. I use a length of chain or a cable lock through a handle or around a thwart and the wooden U to lock them up. Not perfect security but slows down a snatch and run for sure. Not that we have much trouble with that normally out here. But you never know. The only problem I've had is house finches like to build nests on the bow and stern caps of the tandem if I don't use it often! Even hurricanes and the big storm wind of a few weeks ago haven't budged the boats like this. The one under the side porch is wide and holds 2 boats plus my extension ladders. Think upside down ladder rack for a pick up truck.
KISS Principle = Keep It Simple Stupid.
Your best defense against Murphy's law!