Either of a pair of surfaces that are in contact in a joint.

plural of Morin surface

(topology) A halfway model of the sphere eversion, featuring fourfold rotational symmetry.

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.

(physics) The layer of molecules at the surface of a liquid that is responsible for surface tension / (ecology) The layer of surface water that forms a boundary between sea and air

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

plural of surface boundary layer

In a steam boiler, the aggregate surface exposed to fire or to the heated products of combustion, especially of all the plates or sheets that are exposed to water on their opposite surfaces.

plural of surface plasmon

A military (naval) vessel designed for operation on the marine surface, as distinguished from a submarine or other types of vessels. Aircraft carriers are also generally excluded.