The CAVIAR campaign will be part of a large consortium which includes theoretical studies of the water dimer, FTS and Cavity Ring Down measurements of continuum absorption in the laboratory and modelling studies of the impact of the continuum on the Earth's radiation budget for present day and possible future climates. The CAVIAR campaign will use instruments on board the FAAM BAe-146 aircraft to determine the strength and temperature dependence of the water vapour continuum over a range of wavelengths. In doing so, the aim is to determine whether water vapour dimers, or the far wings of monomer lines, or a combination of both, are responsible for the continuum absorption, and put the continuum on a more secure theoretical footing.