The Rigelian scout ship was a Federation starship type in use by the Rigelian Trade Commissions in the mid-22nd century. Ships of this type were heavily armed. Rigelian scout ships were gray, slender, conical vessels with two warp nacelles. (ENT episode: "United"; ENT - Rise of the Federation novel: Tower of Babel)
In mid-November 2154, a Romulan T'Liss-class telepresence drone ship disguised as United Earth Starfleet vessel Enterprise attacked and destroyed a Rigelian scout ship as part of a mission to sow dissent between local species. 17 Rigelians perished in the attack. Captain Jonathan Archer of the real Enterprise and his allies foiled the Romulan stratagem and revealed them as the perpetrators. (ENT episode: "United")
On April 2, 2163, two Rigelian scout ships were part of an international task force led by Federation Starfleet formed in response to the Mute crisis. The two scouts successfully harried a Mute raider after it had been found by a Xarantine task force vessel. During the assault, one of the scouts was damaged.
On April 5, the Vertians responded by surrounding the allied task force and demanded the return of their crewmembers the allies abducted from the captured raider. To prove their point, the Vertians destroyed one of the scout ships. On April 6th, Captain T'Pol of Federation starship USS Endeavour "negotiated" the release of the task force by the Vertians by returning the Vertian captives and turning herself over for atonement. (ENT - Rise of the Federation novel: A Choice of Futures)
On June 19, 2164, Teixh Veurk, official of the Colonial Port Authority, directed three Rigelian scout ships to Colony 1, a moon of Beta Rigel VI, to assist the Federation UESPA Starfleet starship USS Pioneer in tracking down criminals in the Beta Rigel system. The three scout ships helped Pioneer corner the fugitive Grennex G-7, and Starfleet captured its Suliban pilot. (ENT - Rise of the Federation novel: Tower of Babel)