The Section 31 fleet is a fleet in service to Section 31.
In the 22nd century, the United Earth Starfleet splinter group got its hands on the blueprints for Enterprise before its construction and launch in 2151. The pre-Section 31 had their own small fleet of Warp Deltas or its less commonly known name the Ganges-class, several Intrepid-class cruisers, and at the beginning one NX-class vessel with no markings and stolen adapted Klingon shields, cloak, and disruptors.
The flagship of the splinter group was known as the Stalker. It could travel with its adapted warp technology at warp 5.7 at maximum speed at original construction. The Stalker and the rest of the splinter group's fleet mainly were stored in large docking bays and drydocks in a nebula on the outer edge of Vulcan territory. The fleet engaged in several secret battles with Romulan and Vulcan vessels, but due to the xenophobic and secretive traits of Romulans, and the Vulcan's deduction that the Earth ship fleet was not from Starfleet, United Earth Starfleet never learned of these incidents.