The  Casualty Returns  refer to the total losses of ocean going merchant ships over 100 gross tonnes. The Returns were published quarterly and annually, recording losses according to flag and cause of loss. Early  Quarterly Returns  give figures for steam and sailing vessels by flag and cause of loss, and for total tonnage owned in each country. Later editions also show the year of build (since 1928) and ship type (since 1939). To gain a deeper understanding of the information found in our Register Books, we recommend viewing our 'Interpreting the Register Books' guidance alongside viewing the Register Books. Please click the link here:https://hec.lrfoundation.org.uk/archive-library/interpreting-the-register-books