?Let's salvage Sea Diamond? lab presents a software for the study of floating / sinking as well as of density as a property of materials. The structure of the software is defined by a scenario, based on the accident of the cruiseship ?Sea Diamond? in spring 2007. In the eleven ?rooms? of the software the users can control the possible variables that could affect floating / ­­­sinking, search information about technological materials (e.g. polyourethane), use a visual model of density to explain and / or predict floating / sinking, try to salvage the simulated model of ?Sea Diamond? etc. The users of the software use models and implement the Distinction and Control of Variables method. Furthermore, they discuss about them so as to learn in depth aspects of the scientific method. While working in the laboratory, the participants will be able to use the software together with the relevant worksheets as well as to discuss about the possibilities of its educational exploitation.