I've only used the kayak stacker to transport 1 kayak about 9 feet in length, accompanied with the Yakima bow/stern tie downs. It holds the yak very tightly. I've driven only several miles, but have not had any problems thus far. (Knock on wood.) Everything fits snug and secure as long as you follow the instructions. Supposedly you can use the stacker for up to four kayaks or two canoes. I plan on purchasing a second kayak for my girlfriend, and there is definitely enough room and strap length to support both securely.

I've had my Stacker for one year and used them for short and long distances(Maryland to Maine). I have never lost my boats (carry two Heritage kayaks), but have had to stop and re-adjust many, many times. Works well, but I'm still looking for a better solution.

Works well – its ability to hold multiple kayaks is economical feature. You need to ensure that clamps tightened securely. Strapping procedure slightly complicated but not onerous.

I've used the stacker and like it alot, It moves out of the way when not in use unlike the "Hullraiser". You have to really get the wing nuts tight but thats a small issue. When you add some pads and a "Boatloader" single person loading and unloading is a breeze!!! I have a tall vehicle and stand only 5'8" so this set up was a must for me. If you have a Poly or roto-molded boat stay away from the dent prone "rollers" and BUY THIS PRODUCT! ...two thumbs up.