Basic concepts include mass and momentum conservation, hydrostatic and geostrophic balance, and pressure and other vertical coordinates. It covers the topics of fundamental conservation and balance principles for large-scale flow, generation and dissipation of quasi-balanced eddies, as well as equilibrated quasi-balanced systems. Examples of oceanic and atmospheric quasi-balanced flows, computational models, and rotating tank experiments can be found in the accompaniment laboratory course 12.804, Large-scale Flow Dynamics Lab.