Drifting Ships are made mostly by the Kobolds, but other people with enough knowledge of a Surge workings may build them as well. Drifting Ships navigate the Surges as Tuned Ships navigate the Tides and Carved Ships navigate the Streams. These vessels must be made with materials touched by the Surge they are supposed to sail on, and they can float only on that particular Surge (it may happen that a Drifting Ship built in one Surge proves to be able to navigate a very similar one, but it’s highly improbable that the same boat comes in contact with -let’s say- two Wind Dragons or something like that).
The fact that Surges are mostly very limited in dimension (and often in duration) prevented a full scale diffusion of this kind of Ships, which are mostly small and confined to very clearly defined areas.
A notable exception is constituted by Kobold made vessels: since each Kobold serving a Dragon is a Drop of the Surge that Dragon casts, their Drifting Ships are able to navigate almost anywhere, provided enough Kobolds (or Kobolds powerful enough) are on board at any sailing time (that’s why Drifting Ships are often called Kobolds Ships). Since number is the main strength of the Scales (as Kobolds call themselves), that’s usually not a problem, but it’s relatively common to see a Kobold Ship’s hull half buried in the earth when most of it’s Kobold sailors disembark (or die – as pirates know); of course, the ship can sail again when (and if) they’re back onboard.
Creation of a Drifting Ship usually requires building the Ship in the Surge or with materials touched by it and completing various rituals, which can be different according to place, practitioner and Surge, and that ultimately consist in dedicating the Ship to the Surge’s Source: a connection between the Ship and the Source must be forged. That’s why Drifting Ships are so much cheaper and faster to build than any other non-mundane ships.
Sometimes, though, Drifting vessels may be created by accident, when a Surge passes through something relatively boat-like under obscurely favorable circumstances.
While surrounded by the Surge they’re dedicated to, or bathed by enough Drops as if it was surrounded, a Spirited Ship is not restricted by the medium it navigates, which can mean a Kobold Ship may sail on water, land or even air (provided it finds some way to sail upward, since it basically floats at the height it is and, in order to go up or down it must some how be pushed in that direction). Note that a Kobold Ship sailing through the sky, falls like a stone if its connection to the Surge is lost.
Since a Surge has a direction, a Drifting Ship inside its Surge is naturally pushed in that direction (hence the name), possibly running aground where the Surge ends. Other than that, Drifting ships need the usual (and unusual) propultion aids to move in any direction (even more to go the opposite way the Surge is pushing).