Lightships (Difinia)
From AdamWiki
Difinia will not be the only fantasy setting this year to include flying ships, for certain. Nonetheless, they fit into my ideas for the world and so they shall be included.
Flying ships are made possible by the magic of lightwood. Lightwood is a kind of wood that grows in a particular area of the world. It seems to be lighter than air. Difinian shipwrights have modified the plan for a sailing ship to accommodate the special needs of air travel. Flying ships, called lightsails, allow the hand of the Difinian Empire to reach much farther than it would with only land-based and sea-based transportation.
The Jienaal Forest grows trees that stretch four hundred feet into the air. They are not necessarily thick trees, though some of the oldest do boast trunks twenty feet across. Many are five feet across -- typical for normal elder trees of eighty feet or less. It seems that the lighter-than-air properties of the trees allow them to grow much higher than normal trees, with much thinner trunks. Lightwood is not a species of tree. Rather, it is a property of normal trees. There are lightwood maples, lightwood oaks, and lightwood elms.
The wood from the trees is not actually lighter than air. Instead, it seems to create a kind of antigravity effect that pushes the trees upwards. Indeed, turning the wood upside down causes it to become very heavy and pull itself towards the ground as if it were more than twice its normal mass. Alchemical research has shown that the liquid in the wood causes the anti-gravity property. Alchemists have tried to extract the juices, but they do not seem to create their intended effect outside the wood. Seemingly, the combination of the plant juices and the wood structure is what creates the effect.
Shipwrights learned how to build ships that take advantage of the lightwood effects. The important design changes were turning the planks vertically to point the direction of the push towards the ground and a special keel that allows the boat to be steady in the air. The lightwood in a flying ship is usually in the sides of the boat, not in the bottom. The keel uses lightwood to push the boat against the wind so that it does not drift sideways while tacking against the wind and to steady the boat so the wind in the sails does not flip the boat over. In most cases, the weight of the boat opposes the upwards push of the lightwood and this acts as a cushion of water might.
Special walls of lightwood hang from the center of many lightsails. These walls, called pushers, can be moved to the fore or aft to lift one end of the boat more than the other. These are used for acceleration and braking. Lifting the front of the ship makes the vessel act as if it were sailing "uphill." This makes it slow down. Lifting the back of the ship causes it to fly "downhill" and speed up. When the pushers are lifted outwards like wings, they stop pushing down and the boat slowly drifts down to the ground. Most lightsails are set up so that they are naturally buoyant under a full-down pusher, but they sink when their pusher is removed.
The Difinian Empire has a navy of fifty lightsails of different sizes and classes. There is no other state that has a navy that approaches the Empire's power in the air. This is clearly the reason the Difinians run the Empire. In addition to fighting vessels, Difinia and many other countries sport lightsails for commerce and trade and personal travel and recreation. The wealthier noble families have a flying luxury yacht or racing air boat of some kind. Most merchants prefer to ship goods by air rather than by ground or sea.
Not many private citizens own lightsails. Lightwood itself is very expensive. The process of treating it to keep the magical liquid from evaporating ("juicy," as sailors say) is also reasonably expensive and must be repeated every few months. Only the wealthiest can afford a lightsail of any size. In addition, many cities and states regulate or outlaw private ownership of flying vessels. Many merchants do not own their lightsail vessels, but pay a portion of profits to the boat's owner, usually a wealthy member of the nobility or royalty.
