Loading a yak on a tall vehicle such as a SUV can be a chore and often requires a small footstool or ladder of some sort to avoid throwing your back or shoulder out. A big help in loading is the bar extender system that both Thule and Yakima market. Thule calls theirs an "Outrigger (#547)", while Yakima sells theirs as the "Boat-Loader" (#4018). They both involve an extension bar of some sort that sticks out to the side of your vehicle so you can place either the bow or stern of your yak on the extender, and then lift the other end on to the rear bar of your rack (see photo below). They both work in pretty much identical Fashion.
However, like most Thule and Yakima stuff, they are a bit pricey. Here is a way you can make your own without much cost. I have a Thule rack with rectangular bars (Yakima uses round bars), and happened to have an extra bar when I moved my present rack from another vehicle. You could also use, as an extender bar, a piece of PVC with a wooden dowel or a steel or aluminum rod inside to strengthen it, as needed. Or you could use an aluminum or steel rod alone as the extender bar. I found a couple of SS 3/8" bow/stern eyes (U-bolts) at K-Mart. One set was attached to the center of the front bar of the fixed rack, while the second was attached to end of the same fixed bar. I attached the curved end of the eye to the fixed bar, and snugged up one of the base plates to this bar with the included nuts so it would be good and tight. Then I slid the second bar (the one to be extended) into both of the U-bolts.
I then attached the second base plate that came with the bow eye assembly using a slightly loose attachment on the middle U-bolt (so the bar would slide easily), and two wing nuts on the tag end U-bolt (all with flat and lock SS washers). Or you can use wing nuts on both U-bolts. These wing nuts can be quickly unscrewed by hand, and the bar slid out for loading, yet hold it very tightly while underway, or while loading and unloading. The plastic end caps on the Thule bar tend to prevent it from coming out of the middle U-bolt (you definitely do not want that to occur!). Where you place the middle U-bolt will determine how far out your bar will extend. On the far (loose) end of the extender bar while underway, I used a small Velcro strap from West Marine to snug up this loose end of the bar to the fixed bar to avoid vibration problems.
To keep your yak bow (or stern) from dropping to the ground while loading or unloading (very uncool!), you can attach a fold-down load-stop or corner bracket of some sort on the extended end, or build your own. The idea here is to provide some sort of elevated stop on the end of the bar to keep the gunnel of the yak from sliding off the end of the extender bar while you are swinging the other end on or off your fixed rack. I happened to have a couple of older model steel Thule load stop corner brackets (#503) that worked just fine, and I used these. They can quickly be attached or removed with a single bolt. I included a photo below, so you can get an idea of how you might want to construct your own, or you can buy a set of these directly.
