I'm trying to determine what sort of motor boats were used by the Japanese during the crossing of the Johore Straits in Feb 42. I know the main force assembled in the Skudai River area, and I know they had some collapsible boats but according to Tsuji and Frei they also had motor boats numbering between 150 and 300 (depending on which source you choose). Has anyone any info on these motor boats - size, construction, were they collapsible military equipment or locally-procured vessels?