The Xindi-Aquatic scoutship was a Xindi-Aquatic starship used in the 2150s. It was much faster, and more maneuverable then the Aquatic's main cruiser. It was also heavily armed with antimatter torpedoes.
The Aquatics sent several vessels of this type among their fleet to assist the Earth-ship Enterprise fight the Reptilians and stop the Xindi superweapon. (ENT: "Azati Prime", "Countdown")