船 chuan2 boat
舱 cang1 cabin
picture of the boat itself on the left seen from the top 舟zhou1
picture of the cabin of the boat which is on top of the boat seen from the side 仓cang1
=舱cang1 the granary character here is reused as a phonetic element AND as a pictorial element. Anicent Chinese granaries and the cabins of sampan boats looked a bit similar (woven roof, round walls)
船chuan2 in some fonts the ji1几table on the top right of chuan is represented with ba1八eight
I hate it when Chinese characters have alternative forms but they sometimes do so we have to learn to cope with that.