This is my very, "High quality" diagram describing the FTL travel in my story series "Endo-Stellarz"! Below is a textual description that goes into more details.

Velinum Skim Drive
Using Velinum as a fuel for a “Skim Emitter”, spaceships create a “Skim Bubble”, a special spherical bidirectional portal that co-exists across two dimensions. Anything within the bubble is transported into a separate dimension nicknamed “Skim Space”, but due to the fact the “Skim Bubble” transmits light as well, it’ll appear as if no dimension jumping has occurred. Any matter that passes through the Skim Bubble’s membrane will find itself transported into the contained bubble in the other dimension if passing into the bubble, or returning to its respective space when leaving the bubble.
“Skim Space” is a dimension that seemingly has a smaller absolute size in comparison to Stellarz, meaning distance traveled within Skim Space is amplified in Regular Space. The “Skim Bubble” will appear in the same proportional absolute location in both dimensions, but due to the absolute size difference, any movement done in Skim Space is equivalent to a much larger distance in Regular Space.
Since any ship propelling itself is technically within Skim Space the ship moves itself and the Skim Emitter through Skim Space at its sub-light speed, thus the Skim Bubble containing displaced Skim Space will move proportionally further within Regular Space. As the Skim Bubble moves it will pick up and drop matter that passes through its membrane. For the most part this causes a slow build up of particles on the ‘front half’ of the Skim Bubble when a ship is traveling.
The Skim Bubble will distort itself to keep any object originating from Regular Space on one side of the portal, whichever distortion requires the least change in the bubble’s shape. This means that large objects will, over the course of a few instants in most cases, push the bubble inward before the bubble quickly engulfs them, successfully transferring them to the other side.
No one knows what is exactly in Skim Space or anything about it except for the fact it appears to be physically smaller and linked to Regular Space.
Visually, the “film” of the Skim Bubble will change visually in accordance with the Relativistic Doppler Effect, meaning within the bubble, the face of the bubble that faces the direction it is moving, will glow much brighter than normal, while the opposite face will appear pitch black as no light can enter the back end of the Skim Bubble that is faster than light. Outside of the bubble the opposite is true with the front of the bubble appearing pitch black while the back end is much brighter. Most ships have advanced sensors to show what would be visible if light traveled instantly on their cockpits.
With modern engines, the Velinum Skim Drive can get an average ship to travel between 4 Gx and 6 Gx an hour. (1,753,200 c to 2,629,800 c) At those speeds a trip between Tharum and Xylon would only take around 65 hours.