Barnacle ships are seafaring vessels, essentially smaller versions of their normal sailing canoes, used by the Keleta-Ru gnomes of the Wounds. While barnacle ships sometimes have small sails, or else carry oars, neither of these are their primary method of propulsion. Rather, they travel by attaching via grappling hooks to other, larger ships, which then carry the gnomes towards their destinations.
The Keleta-Ru make every effort to ensure their presence is desired, never attaching the barnacle ships to others if they are not wanted. For the most part this is eminently practical, as almost all barnacle ships lack any forms of weaponry, and even if they did all they would do is damage the larger host ships they rely upon. Gnomish seafarers aboard these vessels typically join the crews of the host ship while they are attached, asking for little besides food and water, and sometimes not even that.
A barnacle ship may use multiple vessels on its way to its destination, detaching from one and attaching to another as is convenient.