The USS Merrimac (NCC-61827) was a Federation Nebula-class starship that was in service with Starfleet in the mid-24th century. Commander Rudman was an officer serving aboard the Merrimac in 2369. (TNG: "Birthright, Part I")

In 2366, the Merrimac was assigned to personnel transport duties; it ferried Ambassador Sarek and his entourage back to Vulcan after the successful conclusion of a treaty on Legara IV. (TNG: "Sarek")

In 2367, the Merrimac was on special assignment with the Vulcan Science Academy. (TNG: "Brothers")

It later served in Captain Picard's task force to blockade the Klingon-Romulan border during the Klingon Civil War in 2368. It was positioned between the USS Ahwahnee, USS Hornet, USS Charleston, and USS Tian An Men. (TNG: "Redemption II") Later that year, the Merrimac transported Cadet Wesley Crusher back to Starfleet Academy on Earth. (TNG: "The Game")

In 2369, the USS Enterprise-D was supposed to rendezvous with the Merrimac, so a rendezvous schedule was transmitted to Cmdr. Rudman. (TNG: "Birthright, Part I")