You see, Lewis had the skin-boat coracle in mind before he left Washington.
"The Young Alaskans on the Missouri"
Emerson Hough
Weird myths of the great fishes which guided and propelled the coracle-like boats of the first Buddhist missionaries to the shores of Java are perpetuated in stone, and the forest, sloping down to the wave-beaten coast, shows the rich vegetation which still clothes this island of eternal summer.
"Through the Malay Archipelago"
Emily Richings
A lonely fisher in his coracle Came round a headland, lifted on a wave That bore him through the shallows to his cave, Nor other being he saw.
"Elves and Heroes"
Donald A. MacKenzie