Abstract: A pneumatically adjustable pedestal for a boat seat comprising an assembly of telescoping sections, the assembly comprising a cup-shaped base section adapted to be inset in an opening in a deck of a boat and having a flange bearing on the floor around the opening, and intermediate sections and an upper end section adapted pneumatically to be raised and lowered, the upper end section being adapted for mounting a boat seat at its upper end, each successive section from the top down being retractable into the next section below, whereby the seat may be lowered to a level adjacent the deck, the sections being pneumatically upwardly extensible.