Paper short abstract:

Based on ethnographic work in a village on the Bay of Bengal, I describe mathematical practices in the hand-building of wooden deep-sea fishing boats using traditional tools and technologies. The boat builders are craftsmen with practically no formal schooling, minimal tools, and generally no blueprints or other specifications on paper.

Paper long abstract:

There is historical evidence of boat-building in India for thousands of years. The construction of these vessels has adapted to various innovations; in today's world, they are equipped with motors and technologies for communication and GPS navigation. Thus, the men who make these vessels may be using old and traditional techniques and simple tools, but the process of construction is not static. Rather than exact reproduction of techniques of construction that they have picked up in learning their trade, their success depends on problem solving around novel tasks (such as installing an engine) and on adaptive use of tools and materials available.

I share an ethnographic investigation of this vernacular engineering of boat building in coastal Bengal. Typically, a team of eight to ten men, varying in age and experience, works together for four months of the dry season to make boats some 60 feet in length. Teaching and learning are based on informal apprenticeship. The men, often related or from the same village, work in teams with clear understandings of their roles. They share simple tools, help one another, and offer friendly criticism. Most are functionally illiterate, having had little schooling. I have seen no evidence of recorded drawings, plans, formulae, or indeed book-keeping. They report that everything is kept in the head and transmitted orally.

The rigor that a formally trained engineer might consider lacking in their work contrasts with another form of rigorous validation; the boats are exceptionally functional and strong, and used for extended oceanic travel.