Not sure what type of yak ya got but many,many years ago I bought possibly one of the very first Chapman pirogues built,got neat foam block roof carrier with two ratcheting straps and nylon rope and was easily able to transport about 14 ft Chapman using foam blocks(4)and they fit perfectly on gunwales and the ratcheting straps held bow and stern and for extra-stability could tie down pirogue with nylon rope.Just took look on Amazon Prime and looks like Atwood has similar set-up for all of $29,probably would work and Amazon listed bunch of options but would require some type of existing roof rack.Hope dat helps!!Yakima is a company dat specializes in yak-transporting gear,might wanna check em out!!
Mandevillian