Carved Ships are made mostly by Sophians, whose dedication to shipbuilding is one of the main reasons they are called Halflings of the Docks. Only the deep and intuitive mind of this learned bloodline can easily perceive and understand the flow of the Streams. Halfling vessels are made through a mysterious blend of arcane rituals, deep spiritual principles and fine shipcraft. Ships built this way can navigate the Streams the same way Mundane Ships navigate the seas and Elven Ships navigate the Tides. For the ship to float in the Stream, it is necessary that most of the hull and crucial parts (such as oars and anchors) be made from materials that have been significantly exposed to the energies associated to the Stream the ship is meant to sail on (“significantly” may be open to various interpretations: the materials might be native of the Stream’s area, they might have spent there a great deal of time, they may have been exposed to a strong Surge of that energy for a brief but meaningful moment, and so on). The exposure must not be from the same Stream the boat is meant to sail on, it may be from another Stream of the same type (if such stream exists) or from direct exposure to the associated dimension or force. With regard to propulsion and falling off board, the same rules about sailing the Tides also apply to sailing the Streams, save for the fact that Streams have a direction, so Flowing Ships can be carried in that direction by the current (which can be irregular and dangerous) and may find harder to go upstream.
Halfling ships (as they are often called) that float on more than one type of Stream can be made, but they must be built from materials exposed to all the intended Streams or a perfect equilibrium of differently exposed materials must be realised (and every single material must be present in enough quantity to keep the whole structure on the surface or nasty things may happen).Despite the complicated process, building Carved Ships (so called due to the arcane symbols that cover most of their surface) is far more faster than building Tuned Ships (provided the necessary materials are at hand), so they are becoming increasingly common in areas where the Streams are accessible.
Even though it’s not strictly required, Sophians tend to build their boats in wood for two reasons: frist, it’s often an easily accessible Stream-grown material, and second, they consider smart (and they know what smart means) to build ships that can float on water. This way they opened many new commercial routes by sailing Streams up or down to and from the sea.
Halfling Ships can’t go up and down without the employment of specific spells or external means (such as a Dragon pulling up the boat), so the bold Halflings who sail on the Ethereal Streams in the sky to establish commercial routes between different Cloudlands, do so by skillfully maneuvering between different ascending and descending currents (an impressive but rather risky business, ‘cause in the space between two streams they simply aren’t floating).
Of course, most uneducated people don’t perceive a difference between Tide Sailing and Stream Sailing, and thus consider Halfling Ships just a minor, less efficient and less expensive version of Elven Ships.
Carved Ships are of great commercial value even once they’re irremediably destroyed, for their Stream impressed materials can be well sold to Spiritist for their enchantments (and pirates know too well).
Note that a Tuned Ship that sailed the Tide of Light is entirely constituted by materials suitable to sail a Light Stream (and pirates know that too).