Нашел вот такую справку:

44/03/30 strike Palau sinking:

at Palau:
DD Wakatake
AR Akashi
PC Nr 6
aux PC Cha-22, Cha-26, Cha-53, Showa Maru #5
patrol boat Nr.. 31
AN Nishho Maru #5
AKV Goshu Maru
AP Gozan Maru, Nagisan Maru, Raizan Maru, Ryuko Maru, Shinsei Maru #18 AO Ose, Sata, Iro, Akebono Maru, Amatsu Maru, Asashio Maru, Unyo Maru #2
guardboats Ibaraki Maru, Seiei Maru #2
ARS Urakami Maru
torpedo transport and repair ship Kamikaze Maru AK Chuyo Maru, Kibi Maru, Shoei Maru, Bichu Maru, Teisho Maru at Angaur:
small craft Akita Maru #3, Chichibu Maru, Yae Maru, Toku Maru, Kiku Maru, Hinode Maru, Yamato Maru, Ume Maru, Akebono Maru.
damaging PC Ch-35, AN Shosei Maru, AO Hishi Maru #2, AK Hokutai Maru at Palau

Которая говорит о том что Yamato Maru не просто транспорт.