FTL travel in the Radivan world is by jumping through wormholes, using a device called the Choi drive, named after the discover of the wormhole near Earth. The nature of the wormholes is not fully understood, in particular, there is much dispute whether they are natural features, or constructed by some alien race for which there is little other evidence.

Wormholes connect two points in space together, making it possible to travel between the two ends of the wormhole nearly instantly. There appear to be no distance limits on the seperation of the two ends. Typical range for the jumps are tens of parsecs, but distances of over a thousand are known. The Merlin IV system is notable principly for having both ends of a wormhole in its localspace.

The three dimensional space that we live is apparently suspended in a seven dimensional super-space. The boundary between the 7D super-space is somewhat porous at the wormholes, perhaps because the super space is folded against itself at these points. To jump through the wormhole, a jump ship uses its jump field generator (very big ships have two field generators) to fold the space around the ship through the wormhole. There are four ways the field can fold around the ship. Depending on the direction of the field folding, different things happen. Two of the directions, called "Up" and "Down", even though they're seven-space foldings, often don't do anything. This has long been a source of puzzlement. The other two foldings, "Clockwise" and "Counter-Clockwise", result in a trip through the wormhole. For about 1/2 of the WHs, the trip is to the same distant WH, whichever folding is used. For the other half, the distant WH is different for each folding. Some of the singely-connected WH pairs, the orientation in distant localspace is different between the foldings. This is advantagous, because it allows the wormhole to be used for traffic in both directions simualtanously, without risk of collision in localspace.

Most wormholes have a limit on the width of a ship passing through, of about 40 m. That's led to a very standard configuration for ships -- a long cylinder. Field generators can produce a field of about 1200 meters long, which puts a limit on the size of ship. (Though very large ships have two generators.) The typical commercial cargo ship has a bridge, crew living space, and power forward. Aft of this is a spine for cargo containers till roughly mid-ships, where there is engineering space, the Choi drive unit, and major power. Aft is additional cargo spine, the normal space reaction drives and fuel. The spine is a regular hexagon, with a side length of 10 m. One cargo container is attached to each side. Standard container length is 20m, but half-length and double-length containers are common. Containers provide a standard 8X8X18 m space, though they're pie slice shaped. The non-cargo volume provides for climate control, limited power generation, and sometimes life support; bulk cargos not sensitive to climate are often hauled in specialized containers with none of that. Access into each container is provided by a personal-sized hatch, as well as large openings on each end. Most ship's spines are designed to provide access to the hatches, though usually not through an airlock. The spines of cargo ship provides space for their hydroponics, and other life support. At roughly 250 cubic meters volume for each meter of spine length, even the smallest container ships have tremendus volume.

Passenger ships are normally configured with passenger space from the crew spaces back to the mid-ships engineering space, with cargo aft of that.