Nova class refit

Appeared in Star Trek: Yes
Which Episode: Star Trek Voyager Season 7 Episode 25 - Endgame
Canon vessels:

• USS Rhode Island (alternate timeline)

Changes from original class:

• One of the two decks has been changed to a holodeck
  
• Equipped with a Class 7 Warp Drive, capable of reaching speeds up to Warp 9.5
  
• Other changes to make the Nova class suitable for deep space exploration

Description:
The Nova class vessel was originally designed for small scale planetary missions, but the advent of the Dominion War made it necessary to create stronger ships. The Nova class was one of many vessels that Starfleet decided needed to be refitted to suit these needs. The refits were as simple as adding a holodeck and installing a Class-7 Warp Drive and other simple changes, but the results were amazing. This refitted version of the Nova class was found to be capable of deep space exploration, and since the end of the Dominion War that's exactly what it's being used for.