The Hobie-18 presented a difficult situation here because of the way the tramp halves hook in. I tried to find out what he stock 18SX way to do it was to no avail. The answer for me ended up being a spare rear magnum wing mount that I had. This ended up making a stud that sticks forward that you a pole with a hole in it can fit on. For my case, I used an old gooseneck vertex on the stud, then drilled a hole from side to side on the pole, then ran a bolt through the pole and vertex. See attached photo.