Operation "Buccaneer". Note by Secretary. [S.E.A. and I, 7658/DMI]

(ii) Units of two flotillas of Japanese submarines also operate from Penang and reinforcements appear to be arriving in the area. It is possible that up to eight may be operational; of these eight, about four will be at sea in the Indian Ocean on patrol or reconnaissance tasks. The immediate local threat is thus reduced to probably not more than four Japanese submarines. (iii) The immediate local threat may therefore be up to ten submarines. (d) Japanese M.T.B's. are known to be based in the Malaya/ Burma area.