Steth's ship
Steth's ship was a small, lightly-armored Benthan starship which could be operated with a single pilot. It was equipped with an experimental propulsion system known as a coaxial warp drive.

In 2374, the crew of the  encountered this prototype while it was emerging from coaxial warp, and assisted with repairs to its propulsion systems. ()

Background information 
According to the real Steth, as Daelen, in a deleted line, this ship was stolen from the Tactical Flight Group. 

The CGI involved in the design of Steth's ship was done by Digital Muse, under the supervision of Ron Moore. To create the effect of both Steth's ship and a shuttlecraft individually emerging from coaxial space, Moore took inspiration from  and decided to surround each craft in an outline of energy. "To create these ships that unfolded, I decided to do kind of a literal thing, so that a ship would be like origami and unfold," Moore remembered. "We could get a little bit of energy to outline the shape, and then inside it we would see the ship unfold and fill it up. That would give it shape, so you'd have a feeling that it was a ship you were looking at all the way through, yet it was still unfolding. The problem with putting energy on the outside, it makes it harder to see what's inside. So it was a delicate balance [...] Energy defined the shape." (Cinefantastique, Vol. 30, No. 9/10, p. 103)

Showing Steth's ship destabilizing in the teaser involved coloring the energy outline in shades that were unusual for the craft. "I tried to show that [with] color [....] When Steth was having trouble we had a lot of reds and oranges start running through this shell which was normally blue and green," Ron Moore explained. "I've found that in the [compositing] bay, I have some control, and do the final tweaking there. That's what we did with the color." (Cinefantastique, Vol. 30, No. 9/10, p. 103)

The studio model later appeared as a background ship in episodes of Joss Whedon's series Firefly. 

Unnamed starships