Various figures are given for the numbers of U-boats involved during this period; Kemp gives 218 scuttled, and 154 surrendered;[2] Tarrant gives the same.[3] Blair gives 222 scuttled and 174 surrendered.[4] Neistle lists 195 scuttled [5] and 150 surrendered.[6] A number of U-boats disposed of were not in commission; some had not yet been commissioned, some had been decommissioned.