Features of the Black Fleet
The most obvious oddity of the fleet is, of course, the darkness from which it is made. Produced from the liquid light. The process requires magical cold — actual temperature is irrelevant, only the amount of power dumped into it per m³ of light. Once it has solidified, it is powdered, with [setting-specific alchemical bits] added. It is then centrifuged at high power. The darkness left in the center solidifies, and can be worked at high temperatures. Due to its repulsion from light, strong fires or blowtorches are often used to both make it malleable and provide force to work it.
The fleet cannot use conventional fuel sources.[(in sufficiently advanced worlds) combustion or steam power is ineffective due to the light released, and its effect on the ships.] Sails work, but ruin the effect of the fleet – and branding is important to its owners – as well as the stream having little wind most days. Paddles or oars are impractical because the stream is massless; it tends to function as waves more than particles. It remains to be seen if this is for a sensible reason, or a great cosmic pun.
Instead, they rely on the repulsion to light experienced by the darkness the ships are comprised of. A number of mirrors in each ship (location varies) are used to channel light to a fiber-optic cable. This cable is mounted to a system that allows it to rotate on a horizontal plane around a pillar in the 'engine room' of each ship, controlling direction. Separate mechanisms can restrict flow of light, and various methods can be used for short-term light production (it can be funneled from a small box of opaque material without issue, but large-scale use would be more expensive than it's worth).
One large flagship, fitted with supernatural means of communicating with other ships, as well as a high-security vault and various defensive measures.
The original portion of the fleet, created for cargo transport. As a result, they are a little simpler in design. They have a lot of cargo space, of various security levels, and basic accommodation. Each also has a larger suite for the merchant who owns it, the fleet having began as a consortium.
2 or 3 of these follow the fleet at a time. 4 in total exist, with the spares either undergoing or assisting with dry docked repairs, or construction of new ships. All are capable of the darkness production process, and of shaping it. They also have varied options for refining the products traded along the streams, particularly short-lived potions, to sell along the way.
Apart from their materials and production, these are mostly ordinary. The fish of the streams are strange, with special equipment needed for processing to an edible form, but this is housed on industrial ships. The main oddity of these boats is probably in the combination of their light-intake mechanisms with the means fish are taken in from the nets.
These days, one of the larger income sources for the fleet. The larger, named the ballroom, is roughly 75% ballrooms and similar venues, with several musical and 'party' venues. The remaining quater is assorted sports, reading, and eating facilities. The deck holds a swimming pool of 10% liquid light, and is kept well above the main river. The smaller of the two, the Afterparty, is largely given over to bedrooms, with some fishing and reading capacity. Transit between the two is achieved via a number of small shuttle ships. A third is under construction, primarily focused on childcare and schooling whilst parents are on the other boats. There are also to be facilities for adults to learn about the streams. It will be constructed to allow observation of the river through heavily tinted portholes on the lowest deck.
Built to guard the fleet, these have especially sturdy construction. Their weapons focus mainly on using the light as either a weapon or energy source. Though rarely used, they are built to extremely high standards, as the equipment used is difficult to replace.
The most advanced ships in the fleet. They have 45-60% of their surface being covered in mirrors to funnel light into their propulsion chamber. As well as being more hydrodynamic and more powerfully propelled than other ships, their steering mechanism is more advanced. They hold a magically suspended sphere of darkness, with light focused on it from any angle. This can either be controlled manually, or via a panel at one side of the chamber (or partially through each, one controlling direction and the other flow of light). This allows for more complex maneuvers, including limited jumps out of the water, using high-intensity light on the lower hemisphere, or partial submersion. Some varients instead use a set of variously-places light inputs, with control based on flow through each.
There is also a subphotonic vehicle in the experimental phase. Current controls are based both on the usual propulsion, and the ability to reverse the panels that make up the exterior between mirrored faces, and faces of darkness. It has very strongly tinted sheets of glass, which can be pulled down over the windows when it is submerged or about to submerge.
