Society of Naval Architects and Marine Engineers, been investigating the use of various insulation materials, and their proper application, for the purpose of obtaining the most satisfactory comfort conditions on shipboard in the most economical manner. In compiling the data on heat transmission through the various types of constructions as given in this Report, the corresponding "U" values have been based on the latest available information and, technical data supplied by the manufacturers of the insulation and sheathing products now available to the industry. It is recognized that the basic "k" values are subject to change as a result of improved manufacturing techniques and more extensive transmission tests. It is requested that proposed revisions to the Text and Tables be referred to SNAME for preparation of future revised editions of this Report.