The Quick Reference Guide: This reference guide is book 2 from a series of Dredging Technology related books and contains the basic theories and formula's a project engineer needs when acting in the field of dredging projects. It serves as a quick and compact reminder of theories and formulas he needs during preparation, excecution and possibly the handling of a claim during dredging project. The guide is compact and meant to be used on-site. The emphasis of this guide lies on quickly reminding the subjects and being able to quantify the parameters involved. However should there be a need for a more extensive description than a refer is made to the main textbook "Dredging Technology". This guide starts with the basic soilmechanic concepts and formulas which are relevant for any dredging project, such as: Soil stability (retaining walls and quick sand condition), compaction and dilatancy (slope stability and cutting forces) . Next the basic fluid mechanic parameters, such as concentration and density, for pumping soil and water are described and also the parameters of waterjets . Formula's for Pump Production calculation and Degree of Loading of a Hopperdredge are given. The stability of a pontoon, often used on a dredging project, is explained and formula's for the calulation of the metacenterheight are described. A compact description of theories of a centrifugal dredge pump is given together with a description of the pump drive. Especially the specific impact on a centrifugal pump characteristic by a diesel drive is explained. The effect of the pipeline length on the working point and therefore on the effective use of the diesel drive is explained.The effect of a change in the pump impellar diameter or a change in the gear ratio is explained. These are real practical problems on a dredging project and therefore a general procedure for solving a pump question is given. The suction process with the vacuum and the limiting vacuum and cavitation at the pump entrance is described. This is the most important part of the hydraulic transport process, since it is the starting point of the soil volume production in cubic meter per hour when using a suction dredger. The vacuum production is analysed resulting in an optimisation of the suction production. A compact description of an electric generator and motor is given and the difference between DC and AC is explained. The three phase alternating current motor is explained and also the principle of the "Electrical Shaft" is explained. Finally production calculation formula's are given for a cutter suction dredger (CSD) and a trailing suction hopper dredger (TSHD).