The I-400 class submarines were designed especially for
Seiran, the biggest submarines built up to that time (1945). The Panama strike force consisted of I-401 and I-402 carrying three M6A1s each
and I-400 as a fuel tender. There were also two smaller subs carrying two aircraft each. I honestly don't know if they were Seirans or smaller
Unfortunately for the Japanese, the war ended while the strike force was en route to Panama.
I'm not going to post the pics that I have taken of Seiran here that are already on
and this page
That is an AMAZING site if you like Japanese aircraft, it has more than you could ever want to know!