It is said that the master brain behind building shades over the boats, was that of a British man, who on one of his journeys across the waters suggested this idea to build bamboo roof overhead.
https://touriism.travel.blog/2020/04/12/20
Kettuvallam — houseboats (literally in Malayalam ‘Kettu’ means “to tie” while ‘vallam’ meaning “boat”) which can carry more than 25 tons — was the most preferred transport option to carry heavy loads and also take people to remotest of villages via backwaters
Branding Photo 