Abstract: A lifting jack for raising boats and other objects. It has an inner housing or tube which is supported from a flat base. An outer tube is slidably mounted over the inner tube. A hydraulic jack inside the inner tube raises and lowers the outer tube. Two parallel series of vertical catches are supported on the outside of the outer tube. A selected pair of these catches support a connecting rod which holds a pair of flat support arms in a fixed relationship. The arms support a lifting pad in a plurality of elevations for each pair of vertical catches. A safety latch permits the outer housing to be raised but must be manually released for lowering.