The present invention comprises a method, apparatus, and system for modular mounting of typical pontoon or deck boat furniture and accessories including, but not limited to, seats, loungers, helm, bars, tables, fishing pedestals, sun pads storage bins, privacy curtains, lighting fixtures, and the like. The present invention allows customers to easily reconfigure the cockpit as needs or preferences change without leaving unwanted holes in the boat deck. The present invention also incorporates tool-free mounting devices arranged in a grid pattern that allows flexible placement and orientation of typical pontoon boat furniture and accessories. Further, the present invention permits streamlined manufacture by use of uniform, interchangeable inserts and modules.