The best and safest method to transport your boat is on a crossbar roof rack (sport rack). The boat should be tied down on each crossbar and the bow and stern should be attached to each end of your vehicle.
Kayak cradles can be added to many roof rack systems to make kayak transportation easier and more secure.
FOAM BLOCK RACKS
Foam block racks can be used for short distances or lower speed transportation. They should be wide enough for adequate support, as well. Use extra caution with foam blocks as they are not as secure as crossbar racks. Foam blocks also make it essential to tie off the bow and stern of the kayaks directly to the vehicle.