Timeboats

Timeboats are unique to the Sahuul Desert, where their prow lanterns of temporal crystal allow them to sail on the long-extinct oceans. Eons ago the Sahuul Desert was the bottom of a shallow sea before it vanished into time, but the strange crystal lights which adorn the prow of each timeboat allow them to sail over the surface of the desert as if the water still flowed over its surface.

Temporal Crystal Lanterns

The temporal crystals are contained within lanterns made of a metallic ore which is only found near the crystal beds where they are mined. When a boat is starting its journey, the closed lantern is gradually opened and the boat drifts into the air from its landing spot as if it were an air bubble rising to the surface, and the process is reversed at the destination. Great care must be taken during this process, as a lantern being closed too quickly can dash it to the ground from a great height.
Each lantern-core is carefully and precisely carved from a single shard of temporal crystal with special tools, and the fragments are always paired with the lantern. The steering rudder of the ship is inset with offcut shards to ensure it bites deeply into the time-waves, and some shipmasters use other shards along the waterline of their vessel, believing the line of crystal gives them a better feel for the ancient sea through the hull of the ship.

Small but Speedy

Most timeboats are fairly small and even the largest never exceed fifty feet, as otherwise parts of the boat will be outside the lantern's area of effect. Experiments with multiple lanterns were abandoned after mismatched crystals caused boats - and crew - to shear as if sliced with a blade, and crystals that were too well-matched submerged a ship into the temporal flow entirely and it vanished together with its crew. Chronomancers called in to research the disappearance confirmed that the boat had returned to the original oceans, and there was no way to retrieve it or its crew without the crystals mounted on it.
The ships are either open to the air from the keel up or have a low-ceilinged hold below-deck for the larger vessels, a mast amidships to catch the wind for propulsion, and a steering rudder at the rear. Lanterns are always mounted on the prow, after experiments with mounting the lantern on the mast left the ship lurching and jumping as the time-waves pounded it from all sides.

Sailing the Ancient Seas

Sahuul Timeboat Landing by Nathan Turner

Commonly used for long-distance travel, the timeboats float about six hundred feet above the sand and salt-crust, at the level of the original sea surface. They rock in the air as they feel the effects of the ancient waves, and it is not unknown for them to encounter echoes of long-past storms. Boats with particularly potent temporal crystals may allow a shadow of these storms to pass into the present day, as clouds roll in and the wind picks up, causing sandstorms whose gusts and eddies resemble a storm-tossed ocean more than the present-day sea of sand.
Shipmasters in a hurry may attempt to outsail a temporal storm, but only the skilled survive more than a few attempts to do so. Timeboats are just as vulnerable to capsizing in stormy weather as any other sea-vessel, and unwary crew flung from a great height do not have the buoyancy of a timeboat to keep them aloft. Attempts have been made at creating time-belts, with small man-portable lanterns mounted on them, but few of the experiments have borne fruit.
Those aboard the ships can see the ancient ocean around them as if a ghostly echo overlaid on the current time, but there is limited ability to interact with the ocean except for feeling it through the hull of the ship and the rudder controlling its course.

Fishing the Extinct Ocean

Experiments with turning the shards into jewellery resulted in peculiar and often-undesirable effects, but one crystal-carving chronomancer tried an experiment on a fractured crystal. Turning the assorted shards into thousands of small beads, she had a rope-maker weave them within cords. The rope-maker then knotted the cords into a net, which the chronomancer gave to a captain. Curious, the captain agreed to try the net with his crew, resulting in a catch of long-extinct fish. The fish swiftly decayed to dust when removed from the effect of both the prow lantern and the beaded net, but the mage persisted. After some research, she discovered a spell which could bring the fish into the present time. For now, the rarity and cost of the fish reserves them as expensive delicacies for the rich, but the experiments continue.