But mass and attendant stresses scale…Small boats have smaller mass - so any impact can be can throw the whole boat around, spreading the impact forces around more of the structure. And being smaller, have less chance of running aground or hitting any UFO's
Some racing rules require a ceertain sq footage of orange paint on the underbodies for rescue visibility. Has nothing to do with structures.
Edit- so that suggests that the larger boats didn’t scale their fastener/material design