These cradles are free standing and used in 2-3 or 4 in a row configuration, the system can be used on any type of boat, even fin keelers (with the addition of a link bar). It is possible to hold a boat high off the ground safely and to remove individual support pads one at a time to allow for full access to the hulls surface. Easy and quick to set up and take up very little space when stored. Contact us for more information if you are interested in obtaining your own.