Abstract The project ‘Restoring Underwater’ launched and conducted by the Underwater Archaeology Operations Unit of the Istituto Superiore per la Conservazione ed il Restauro (ISCR, Rome, Italy) is aimed at the study and the experimentation of instruments, materials, methodologies, and techniques for the restoration, conservation, and in situ display of ancient submerged artefacts. The project commenced in 2001 with the restoration of the vivaria of the Roman villa of Torre Astura (Nettuno, Rome), since 2003 the main subject of researches has been the submerged archaeological site of Baiae (Naples, Italy), where, over the years, the restoration of sectors of certain buildings in the protected marine area has been carried out: the Villa con ingresso a Protiro, the Villa dei Pisoni, the Via Herculanea, and the Building with porticoed courtyard near Portus Iulius. In 2007, in 2009, and in 2010 three new archaeological targets have been added to the research: a group of nine cast iron cannons discovered offshore the coast of the Marettimo Island (Sicily, Italy), the Roman wreck carrying a load of sarcophagi discovered off the coast of San Pietro in Bevagna (Taranto, Italy), and the traditional fishing boat recently discovered off the cost of Martana Island (Bolsena Lake, Italy). The purpose of this paper is to sum up the work in progress and the results of these ten years of the project. The paper will shows as the conservation and museum display in situ of underwater heritage must not just be considered an opportune choice but may in itself provide a strong stimulus for experimenting new materials and technologies as well as representing a factor in the socio-economic development of the communities concerned, as shown by the example of Baiae.