Why 3D printing will reach ship parts before whole warships

Will 3D printing eventually build vehicles larger than small boats?

Probably, but naval use will mature first in certified parts and short production runs because material performance is harder to scale than the printer.

The machinery of additive manufacturing can be enlarged more easily than the material properties can be guaranteed. A printed vehicle or hull must survive loads that hobby parts and prototypes never encounter. The panel therefore expects metal printing to spread first through ship components, replacements, prototypes, and limited production. Whole large vehicles remain possible in principle, but material science and high-volume manufacture are the slower constraints.