Ipacian Navigators

Ipacian navigators are not a class of vessel, but an entire breed. Ipacian navigators are those ships built to withstand the dangers of Ipacia and actually sail the Realm of Stars itself. With a magical furnace known as the Void Engine, Ipacian navigators can achieve speeds otherwise unknown in Yophas. More importantly than their speed, however, is their ability to plot routes through the shifting non-reality of Ipacia.

Power Generation

Smaller Ipacian navigators need bursts of magic to get going and then maintain their different arcane systems through absorbing ambient planar energies. Larger Ipacian navigators require huge sums of magic to start and keep running, especially those large enough to need multiple Void Engines.

Propulsion

The Void Engine is the crux of Ipacian navigation. Because Ipacia has little regard for spatial reality, the distances and locations of things is never constant. Void Engines circumvent this. They require a large burst of magic -- exact amount contingent on the size of the vehicle -- to activate, then either feed off the ambient magic of Ipacia, in the case of smaller navigators, or require active magical fueling, in the case of larger ones. 
Once activated, the Void Engine must be guided. This requires someone to mentally interface with the Engine and imagine where they want to go. Then, the Engine pushes the navigator through Eriothas, the Ethereal Plane, appearing at the destination within minutes. The difficulty then rises from maintaining the mental connection and withstanding the mental stress, for the person interfacing must keep the Engine on its "tracks." This takes a ridiculous amount of mental resilience, so most people who handle guiding the Engine are known as Wayfinders and specifically train for this task.
Specific fueling requirements can be found in different navigator class articles, as those are written.

Armor and defense

Ipacian navigators are constructed with abjuring wards that allow them -- and their crew -- to survive the magics of traveling between the planes. Smaller navigators keep these wards sustained in a similar manner to their Void Engines, while larger ones need active maintenance and magical fuel.

Ipacian Navigation

Ipacian navigation is the "every-man" way to travel through Ipacia, the Realm of Stars. That isn't to say it is easy, or even feasible for almost anyone, but it is more accessible relative to the other options: psionics or magics that influence time, space, or the planes.