The propeller-driven Type 2 Ka-Mi armored fighting vehicle floated with the help of two large pontoon attachments, one on the front and one on the back. When the amphibious tank got ashore it could theoretically release the latches from inside and jettison the pontoons, continuing inland in its less cumbersome configuration.
In all, 180 of these vehicles were built, mostly for use by Japanese SNLF (Special Naval Landing Forces) units. American forces met some of them in combat on Kwajalein atoll, Saipan, and in the Philippines.¹ I recently completed two Ka-Mi model kits, one with pontoons and the other without. My son and I staged a small seaside diorama featuring these new models.
¹Advanced Squad Leader Rulebook. Avalon Hill Games. p. H91.