Star Trek Expanded Universe

A cloaking device was a device that had the ability to render an object invisible to the naked eye as well as from most sensors.

Kirk and Sulu spot the blurry distortion of a cloaked Bird-of-Prey

Romulan bird-of-prey cloaking


The Federation and cloaking technology[]

The improved Romulan cloak

Following the Treaty of Algeron in 2311, the Federation agreed not to develop cloaking technology. (TNG: "The Pegasus")

In the mid 2360s, the Captain Menchez of the IKS Bochnah loaned his ship's cloaking device to Captain Daniel of the USS Phoenix after Daniel had saved Menchez's reputation and life in the Klingon Empire. When the Phoenix was nearly destroyed in the Tiloniam system, in 2374, it was found that Menchez's cloaking device was salvageable. The device was later re-installed into the X-Project designed starship, USS Phoenix-X. (Star Trek: Phoenix-X: "The Tiloniam System", "Betrayal and Honour", "The Tilonian System", "These Aren't the Voyages...")

Quark's cloaking device

In 2383, the Phoenix-X lost its Klingon cloaking device when the ship became under attack. Following the loss, Section 31 ordered the Phoenix-X to the Mutara sector where an Interphasic cloaking device would be installed onto the ship. (Star Trek: Phoenix-X: "These Aren't the Voyages...")

In 2381, the need for a cloaking device increased with the outbreak of the Coalition War. So Starfleet developed Deflective hull plating or DHP as a replacement to a Romulan or Klingon style cloaking device. DHP was designed to be a state of the art stealth material that could completely cover a small ship. Most of the technology involved was adapted from the advanced technology that had been found attached to the USS Voyager (NCC-74656) upon its return home. The thinking was that since this technology involved hull plating that deflected light from a vessel's hull would not be a violation of the Treaty of Algeron. In addition, computer protocols were programmed that would mask the ship's signature with the surrounding space particles. Starfleet first equipped and tested this technology with the USS Ares (NX-19803) in 2382. (VOY: "Endgame", Star Trek: Pioneer: "The Boolran Eye, Part 1")

By 2410, Starfleet had permission from the Romulan Free State to use cloaking devices aboard Puerto Rico-class runabouts. (Chronicle: "Best Laid Plans")


The Klingon Empire acquired cloaking technology from the Romulan Star Empire as a consequence of the Treaty of Smarba. (Star Fleet Battles)

The Hydran Kingdom, fearing the threat of the Lyran Star Empire and the Klingon Empire, has developed cloaking technology even though it was outlawed by Hydran law at the time. (RIS Bouteina: "Vosteage")

By 2389, the Hydran Kingdom has lifted its ban on the cloaking device, especially after the Kingdom has sided against the Klingons in the Klingon-Romulan war. As such, the Vosteage subclass was equipped with cloaking devices, and all Shogun-class ships were refitted with a cloaking device. However, cloaking devices weren't mass-manufactured, yet so only a handful of Hydran ships actually were capable of cloaking. (RIS Bouteina: "Hystelic Kingdom")

Improvements in cloaking technology[]

The interphase cloak[]

Interphase cloaking device

The Enterprise-D decloaking near a Romulan warbird.

The Treaty of Algeron did not stop Starfleet Intelligence from secretly and illegally developing the interphase cloaking device, a device which not only rendered a starship invisible but also allowed it to pass through solid matter unimpeded. The device was lost in 2358 when the testbed vessel, the USS Pegasus was presumed destroyed by a warp core breach in a mutiny by members of the crew concerned about the legality of the test. In 2370, the Pegasus was found not to have been destroyed, and the existence of the illegal device was made public to the Romulans. (TNG: "The Pegasus") The device was soon handed over to the Romulan government but was destroyed during transport by Mackenzie Calhoun, working for Intelligence. A similar device was developed again, by Section 31, 13 years later and installed onto the Phoenix-X. (Star Trek: New Frontier: "Loose Ends", Star Trek: Phoenix-X: "These Aren't the Voyages...")

The Srivani normally used phased cloaking technology to beam onto alien vessels and run scientific tests on the crew. The Srivani's medical devices were also phased. In 2383, the Phoenix-X encountered the Srivani, who ran tests on the crew until the scientists were attacked by genetically altered interphasic organisms. (Star Trek: Phoenix-X: "Fantastic Method")

Multi-adaptive shielding[]

While it was considered an improvement on the cloaking device by the Romulan Senate (when used in combination with a cloaking device), the Federation was not found in violation of the Treaty of Algeron for the multi-adaptive shielding, since it simply randomly and constantly changed the sensor signature so they wouldn't be targeted by Borg. However, the Romulans did not test the multi-adaptive shielding in combination with their cloaking device until 2384, with the RIS Bouteina as the Romulan testbed for this technology. (RIS Bouteina)

Ships utilizing cloaking devices[]


Individual ships[]


External links[]