An adjustable adapter assembly secures a framework/console to an anchoring fixture. A housing member connected to the framework has two pairs of parallel walls having laterally aligned elongate first slots and laterally aligned elongate second slots, respectively. A clasping mechanism inside the housing member has a shank portion and finger members. First and second threaded orthogonal bores laterally extend through the shank portion, a first threaded bolt extends through the first slots and first threaded bore, and a second threaded bolt extends through the second slots and second threaded bore. Rotating the first and second bolts laterally displaces the clasping mechanism to align the finger members with part of an anchoring fixture on the deck for engagement by the finger members when a locking ring is appropriately displaced. Several assemblies secured to the framework can be adjusted to interconnect with permanently mounted anchoring fixtures in the deck.