As told, the very first component of the warning sea network were the "Contiguous Barriers", created over Eastern and Western North American continent shorelines. The Atlantic Contiguous Barrier extended from Cape Cod to North Carolina, and included 5 stations (12,14,16,18,20), located at approx. 555 kms from shoreline, initially linked to a distinct land-based ADDC (Air Defense Direction Center); from 1959 the system was reorganized from Air Force: station 12 and 14 reported to ADDC at Otis AFB, MA, and stations 16 to 20 reported to ADDC at Cape Charles, VA.
During July, 1956, the DEW Line was extended fron Terranova to Azores, generating the Atlantic Barrier, sustained until July 1961 by CORTRON's DERs; in the meantime was created the COMBARFORLANT (COMmand BARrier FORce AtLANTic), with headquarter at NAS Argentia, Newfoundland, Canada., acquired by the Lend-Lease agreement with the United Kingdom. COMBARFORLANT was also the COMAEWINGLANT (COMmander AEW WING AtLANTic), with responsibility to provide the aircrafts for AEW patrols. The WV-2s of VW11 and 15 were moved to Argentia as well.

The Atlantic Barrier begun operations during summer 1956 with the first patrol of USS Strickland (DER 333) and of WV-2, but it became fully operational only on July 2nd 1957 with 4 stations at a 460 km intervals from Terranova to Azores. 4 WV-2, and 4 ships were always in service over the Barrier.
The WV-2 flew at a 1,500-6,000 m level, depending from the weather conditions: they took off every 4 hours, for a mission 12 hours long, and, in order to guarantee the schedule, a second WV-2 was always ready to take off in 15 minutes, and a third one in 30 minutes. The severe weather conditions over North Atlantic heavily disturbed the operations: if over Argentia the conditions felt below the minimums, the WV-2 could have an alternate field at Terranova (Stevensville AFB), or at the Gander or St.John's commercial airports, or even, in the worst conditions, at Lajes, in the Azores.

The Atlantic Fleet operated with a total of 22 DERs, with a peak of 19 units on line at the same time; this number was reduced to 17 in 1957, because many unit were transferred to the Pacific Fleet. During 1960, a first cut in the expenses brought to the decommisioning of 9 DERs based at Newport, and during January 1962 the CORTRON 18 was decommissioned as well. In 1959, with the raise of Castro's Cuban threat, was created a Southern Tip of the Atlantic Barrier, located 185 km east of Key West, 150 km south of Miami, and only at 170km from Cuba.

The DERs and the AGRs located in that area were in that case linked with Key West CONAD Control Center. During the first half of 1961 were installed new USAF radar land-based sites, that pratically extended the DEW Line eastward to the Greenland; there was a non-covered passage between Greenland and NATO Allied Command Europe Early Warning System that ended in Scotland: to outcome this problem, on July 1st, 1961 the Atlantic Barrier was dismantled, and replaced by the GIUK (Greenlad-Iceland-United Kingdom) Early Warning Barrier and, in the meantime, COMBARFORLANT headqauarterwas moved from Terranova to Keflavik, Iceland. The GIUK, due to delays in the placement of the radar devices, entered in service only a month later, and the Navy was forced to cover this gap with the Atlantic Barrier. The new barrier controlled two Naval Stations and two AEW Stations on the east and on the west of Iceland. The portion between Iceland and United Kingdom was under a constant control of a WV-2, while the portion between Iceland and Greenland was covered only for the 70% of the time, The WV-2 were based at NAS Keflavik, Iceland, with a 2 weeks transfers from Argentia where they returned for 4 weeks for maintenance purposes and for the crew rest.

In Keflavik the meteo conditions often felt below the minimums, and, in these cases, the aircrafts were diverted to Prestwick, Scotland. The patrol turns of the Atlantic Barrier ships lasted 3-4 weeks, with passage to GIUK Barrier, with 2 weeks spent at the station and 2 weeks at Greenock, Scotland. The operation condition were extreme, with winds at 130-150 kmh and waves 12-15 m tall. During February 1962, USS Roy O.Hale (DER 336), engaged in GIUK Barrier, felt into a violent storm, that caused damages to fore turret and ASW launcher, many damages to the structures and 13 men injured, of which 2 very seriously. Despite of weather conditions, the radar signatures where checked against that of the known commercial aircrafts over the North Atlantic, and the non-identified tracks where passed to NORAD, for a closer evaluation, and, if necessary, the engagement of fighter aircrafts.

In particular,while the primary mission of DERs was the discovery of aircraft approaching to North American continent, the secondary one was surface and submarine surveillance: for this reason possible sightings had to be reported to ASW Force Atlantic Commander at Norfolk, VA. The ships had also the task to notice the weather conditions and give radio assistance to civilian air traffic, occasionally participating with "WV-2" to SAR operations.