This is an introductory guide to the basic principles of hydraulics with an explanation of the essential theory which should be ideal for student-centred learning. It should appeal to any student embarking on a course in fluid mechanics having no previous knowledge of the subject. By concentrating on an explanation of the fundamentals, the author aims to give the reader a clear understanding of what happens, as well as why, when and where it happens. At the same time, the author matches the use of mathematics to the topic and sometimes the proof is placed in an appendix in order not to interrupt the development of the main text. In all cases, proofs, derivations, theory and worked examples are given in full, so that the interested reader can follow them through step-by-step. In addition to worked examples, all the chapters contain self test questions (STQ), which are designed to enable the reader to check understanding before moving on to study another topic. There are also revision questions with numerical answers. It is suitable for undergraduate students taking civil engineering, HND courses in civil engineering and building, BTEC NC / ND in construction, building studies, civil