Sea water thermodynamics is arguably one of the most central and fundamental areas concerning oceanography: how should we measure/interpret something as basic as temperature, salinity, heat and/or energy of sea water? The review is a tour de force by one of the leading experts of the subject area, summarising the development of sea water thermodynamics to date (spanning the author's career), highlights important subtleties that oceanographers should know, and provides interesting outlooks for further directions for investigation. Make no mistake, the review is by no means an easy or a short read, and the material will require time and effort to digest properly. This is likely one of those journeys where there simply is no shortcut, but this is an excellent guide to help those willing to undertake that journey.