IJN Transport Subs

I’ve seen mention of IJN subs used for transport ops. were equipped with a Daihatsu landing craft but other than saying they existed there is not much info. Only thing I’ve found just says they were special,water proofed version of the 14 meter boat. Info on I-1 says she had Daihatsu mounts installed in Aug.42. Some Vice Admiral at Chuk (Truk) inspected the set up in Sept. , and it was used operationally twice in Oct. QUestions: did they Daihatsus look any different from the normal ones? What did the mounts look like? Was the cargo pre loaded in water proof containers in the barge so that basically they just surfaced, unhooked the LC and off it went to the beach?