Practical guidance for determination of mass of load on sinking of ship. Methodology over of implementation of calculations is brought in ship terms, with the use of ship information. She allows to define mass of the submerged and unloaded load with acceptable exactness. Exact determination of mass of load allows to promote efficiency of exploitation of freight dry-cargo ship ship, and also to avoid commercial losses from a shortage transported load. This guidance can be used both in educational aims and in practical in the process of exploitation of ship.