Rooftop kayak racks start with a base system, which is composed of two horizontal metal bars that fasten to the top of a vehicle. The bars are designed to attach to factory-installed roof racks, raised side rails and naked rooftops. Some base systems allow extra clearance for vehicles with side gutters, and some specialty systems are made for specific vehicle models. You can attach most base systems yourself by using the clamps they come with; however, some stores will custom-design a base system for your car and install it for you.
Once you have your roof rack, it's time to choose the right equipment to attach your boat to the rack. Saddles are small padded platforms that attach to the rooftop rack and hug the bottom of the boat. Saddles are easy for you to install at home, and they provide a safe, stable ride for your kayak. You can attach a pair of saddles to the front bar of your roof rack to support the bow of the boat and a second pair on the back bar to support the stern, or you can attach a set of rollers to the back bar to make it easy for one person to load the kayak alone. With rollers on the back bar, you can stand behind the car and simply lift the bow of the boat into the rollers, and push the boat forward until it is rests on top of the car. However, rollers need a long roofline to have enough leverage to keep the boat from shifting during transport -- it's best to use two sets of saddles if you don't drive a van or SUV.
J-cradles are j-shaped padded bars that hold kayaks on their sides. Because the sides of the boat are stronger than the bottom, j-cradles have a smaller risk of warping plastic boats, and it's possible to haul more than one kayak if your car has a narrow roof. Some kayakers find it easier to load and unload boats from j-cradles because you stand beside the car and simply lift the boat in and out of the cradle instead of loading it from the back. If you want to use j-cradles but don't like the idea of all that lifting, you can buy a loading system -- these typically require you to raise the kayak just three feet (.9 meters), and then the device lifts it the rest of the way [source: Kisting].
Now that you know what kind of equipment you need, read on to learn how to secure your kayak to your car.