Edward Brown’s ill-considered “hammock canoe,” patented in 1884, can be suspended between trees like a conventional hammock or launched on a river like a bottomless aquatic coffin:
On the sides of the main structure or frame handles or holding means are provided, by means of which the person using the device can support the same while walking or floating with their body protruding through the opening in the netting or floor of the float. In addition to the handles I can employ a strap or band adapted to pass over the shoulders of the person using the device.
It’s not clear to me how someone can walk, float, lie, stand, and carry a boat at the same time. Perhaps I should get one and try it out.