present participle of scratch below the surface

(idiomatic) To look or see beyond what is obvious.

A form of deep diving using an umbilical that supplies air, power and communications from the surface to the diver, who wears a diving helmet. This is the traditional diving with a diving helmet and air hose.

Alternative form of surface-mount technology.

(electronics) A method in which the electrical components are mounted directly onto the surface of a printed circuit board.

Alternative form of surface-mount technology.

(electronics) a flat panel display technology that uses surface conduction electron emitters to provide electrons for every pixel. The electrons strike coloured phosphors to produce a colour image. In a general sense, an SED consists of a matrix of cathode ray tubes, each tube producing a single pixel.

plural of surface-conduction electron-emitter display

(historical) A set of scientific equipments used at the landing sites of the last few Apollo missions to the Moon

Without a surface.