What is the meaning of Clinker-built?

Of a boat or ship: having the hull constructed using planks or plates laid so that each plank overlaps the edge of the plank or plate below it, and in the case of plates, behind it; the planks were traditionally secured by nails which had been clenched (or clinched), that is, after being hammered through the planks the points of the nails were bent to make them unremovable.

Source: wiktionary.org