Hi Walter, many thanks, two dates knocked of the list. I have now identified 256 boats fitted of which there are several blanks in dates fitted and trials undertaken. There six boats of which are supposedly fitted but I have not been able to verify where, when and if trials were undertaken. These being U445, U721, U975, U1000, U1054 and U1198. Of these I have made some theories, U445 being fitted at La Pallice between 06-08.1944, U722 at Gotenhafen 11.1943-12.1944, U975 at Kiel 07.1944-02.1945, U1000 at Hamburg 01-24.04.1944 while U1054 had hers fitted while under construction and finally U1198 at Rensberg 01-04.1945. Regards John