After receipt of the minesweeping "M" for excellence from Commander Mine Forces, U.S. Pacific Fleet and the "Best in Type" award from Commander Mine Flotilla One in 1960 and her selection as "Outstanding Ship" by Commander Mine Division 71 in 1961, IMPERVIOUS spent 1961 and early 1962 in overhaul and conducting training exercises along the West Coast.

The ship spent 1961 and early 1962 on important readiness operations, visiting several West Coast ports, and sailed again for 7th Fleet duty 7 April 1962. After training in the Philippines the minesweeper spent part of July on patrol with Vietnamese Naval units off Danang as the Navy supported the South Vietnamese people in their fight for freedom. She visited Hong Kong and Yokosuka before arriving Pearl Harbor 8 September 1962. During October and November, IMPERVIOUS took part in Operation Dominic I, atomic bomb tests at Johnson Island.  She arrived Long Beach 21 November.

In March 1963 the ship took part in another large amphibious operation, "Steelgate", then worked out of Long Beach before again joining Canadian ships for mine warfare exercises off British Columbia in November. On 8 May, 1964 she sailed again for the Far East and arrived in Sasebo via Pearl Harbor, Johnston Island and Kwajalein on 30 June. During the following five months she participated in exercises with the Philippine Navy and conducted special operations off the coast of Vietnam in support of the American Advisory Unit. After visiting Hong Kong and Subic Bay, PI IMPERVIOUS departed on 31 October and returned to Long Beach via Guam, Kwajalein, Johnston Island and Pearl Harbor on 7 December.

Throughout 1965, IMPERVIOUS conducted training exercises on the West Coast and spent a two month overhaul period in Los Angeles CA. 1 January 1968 found her again conducting operations off the coast of Vietnam. On 20 May she departed Manila for Long Beach via Guam, Kwajalein, Johnston Island and Pearl Harbor, arriving in Long Beach on 24 June.

In January of 1966 the Impervious left Long Beach headed for Viet Nam via Hawaii, Guam and Japan.  During the time off the coast of Viet Nam the ship's company conducted searches of over 1000 junks and were involved in  several firefights with no casualties.  Hundreds of suspected Viet Cong were detained as a result of these efforts.  During that period the ship was also caught in a severe typhoon.  Communications with the Seventh Fleet were lost for approximately four days.  After the seas had calmed IMPERVIOUS found herself in the midst about 15 ships that were searching for her.   At the the completion of her successful deployment IMPERVIOUS returned to homeport in November 1966.

IMPERVIOUS moved to Dillingham Shipyard in Honolulu, HI and placed "In Commission Special" on 30 November, 1968 for a Rehabilitation and Modernization Program. During the next two years, her Packard diesel engines were replaced by Waukesha diesels, a variable depth sonar and and enhanced communications package installed, an air conditioning system provided, the 40MM gun mount removed and the ship's galley remodeled. Following shakedown and fitting out, IMPERVIOUS was placed back "In Commission" and reported for duty to CINCPACFLT on 26 December, 1970.

The early months of 1971 saw IMPERVIOUS taking part in training exercises in the Hawaiian Islands, during which she received the minesweeping "M" for excellence. On 1 October her home port was changed to Guam. The ship deployed to the Far East for duty with the Seventh Fleet on 30 November and conducted patrol operations off the coast of Vietnam. Operation Market Time consisted of inspecting numerous junks and fishing vessels in search of munitions being smuggled into the Republic of Vietnam for use by communist forces.

On 1 January 1972, IMPERVIOUS arrived in Subic Bay, then sailed again to take part in patrol operations off the coast of Vietnam. On 18 May she rescued two U.S. Air Force pilots whose Phantom jet had crashed into the sea outside the harbor of Da Nang, Vietnam. After port visits to Hong Kong and Kao Shuing, IMPERVIOUS participated in exercises with the British Navy, then entered drydock in Guam for overhaul and installation of a new underwater hull on 23 October.

On 1 January 1973, IMPERVIOUS deployed from Guam and arrived in Subic Bay on 7 January. She departed from there on 28 January and arrived off Hai Phong, Democratic Republic of Vietnam on 4 February. In company with the minesweepers USS FORCE, USS FORTIFY and USS ENGAGE the IMPERVIOUS conducted Operation End Sweep, the clearing of U.S. mines from Hai Phong harbor and its seaward approaches. Upon completion of minesweeping operations on 18 July, IMPERVIOUS departed the area and arrived in Subic Bay in July and returned to Guam on 7 August.

On 1 May, 1974 IMPERVIOUS bade farewell to Guam and began a 10,000 mile transit to her new homeport, Mayport FL. Port visits included Midway Island; Pearl Harbor; Long Beach; Manzanillo and Salinas Cruz, Mexico; Panama Canal Zone; Antonio, Jamaica; Guantanamo Bay, Cuba; and Nassau, Bahamas. IMPERVIOUS arrived in Mayport on 5 August and reported for duty to COMMINRON12 as a Naval Reserve Force ship as.

On 2 February 1975 IMPERVIOUS sailed for overhaul in Charleston and entered drydock at Detyen's Shipyard in Wando, SC on 6 February.  She departed Charleston on 25 May and participated in Operation Solid Shield, a multi-service exercise.  She returned to Mayport on 7 June and conducted training exercises during the next five months.  In October IMPERVIOUS left Mayport and arrived in Nassau on 24 October for a celebration of the U.S. Bicentennial.

In January 1976 Impervious departed Mayport and attended the Sandy Shoals Festival in Ft. Pierce, FL.  After participation in training exercises, she departed Mayport in April and attended the Azalea Festival in Wilmington, SC.  On 2 July the ship left again to visit Palm Beach, FL  for the U.S. Bicentennial until 6 July and conducted special operations before returning to Mayport.  During July IMPERVIOUS took part in a VIP cruise sponsored by Commander Mine Warfare Command in Charleston.  On 4 December she departed Mayport for Little Creek, VA for an In Service Inspection.  IMPERVIOUS successfully completed the inspection and returned to Mayport.

In January 1977 IMPERVIOUS attended the Sandy Shoals Festival in Ft. Pierce from 20 January until 30 January.  She participated in Operation Solid Shield and training exercises prior to her return to Mayport in may.  On 6 June the ship departed and arrived in Port Everglades, FL the next day for special operations.

During the first two months of 1978 IMPERVIOUS conducted training exercises from her homeport.  In early March she departed Mayport bound for Charleston, arriving 7 March.  While there the ship participated in training exercises and Operation Solid Shield before returning to Mayport in May.  In June she departed to conduct special operations again in Port Everglades.  In late June she sailed to Saint Simons Island, GA and attended the Fourth of July celebrations there.  She departed on 5 July bound for Port Everglades and more special operations, returning to Mayport on 20 July.  During the following months she took part in training exercises and prepared for a Mine Readiness Certification Inspection (MRCI).  On 2 December IMPERVIOUS departed Mayport, successfully completed the inspection, and arrived in Charleston on 3 December.

On 22 March 1979 IMPERVIOUS took part in the search for a crashed CH-46 helicopter off the coast of Jacksonville Beach, FL.  After locating the aircraft and assisting in it's recovery the ship returned to Mayport.  She got underway to participate in Operation Solid Shield in early May, returning to homeport on 24 May.  During the next six months IMPERVIOUS conducted training exercises, including special operations in Ft. Lauderdale, FL in October.  After receipt of the Battle Efficiency "E", Minesweeping "M", Damage Control "DC", Communications "C", Supply "E" and Engineering "E" for excellence as well as the Golden Anchor award for retention, the ship left Mayport bound for drydock at Bellinger Shipyard in Jacksonville on  29 November.

In May 1980 she sailed for Charleston and took part again in Operation Solid Shield until 15 May.  On 24 June she got underway for Port Everglades for two days of special operations.  After a brief visit in Charleston, IMPERVIOUS arrived in Washington DC on 3 July for Independence Day Celebrations.  On 29 July she departed and escorted Naval Academy patrol craft on a tour of the East Coast with port visits in New York, NY; Newport, RI; New London, CT; and Cape May, NJ before arriving in Annapolis, MD on 12 August.  After participating in training exercises IMPERVIOUS returned to Mayport on 1 September.  From 27 September until 2 October she participated in the Freedom Flotilla, escorting refugees who were fleeing Cuba to Key West, FL.  She returned to Mayport on 5 October.

On 17 February 1981 IMPERVIOUS entered drydock at Atlantic Marine Drydock at Fort George Island.  After leaving the drydock on 11 March, she participated in training exercises out of Mayport and began preparations for an upcoming MRCI.  Upon successful completion of the MRCI in April she once again got underway for participation in Operation Solid Shield.  After her return to Mayport she was again assigned to escort the Naval Academy patrol craft on another tour of the East Coast in June.  Port visits included New York, NY; Port Jefferson, NY; Pictou Nova Scotia; Boston MA and Washington, DC.  On 1 October the ship departed Mayport and participated in training exercises in the Caribbean Sea.  Port visits included Saint Thomas, VI; San Juan , PR and Guantanamo Bay, CU before returning to Mayport on 23 November.

The ship departed Mayport in early June, 1982 bound for Panama City, FL.  She arrived on 8 June and conducted special operations until 30 June.  During the homeward transit to Mayport, the ship's company participated in a burial at sea.  She returned home on 3 July, departing for Panama City again on 23 September where she conducted special operations.  During 1982 IMPERVIOUS received the Operations "E", Communications "C", and Supply "E" for excellence along with the Golden Anchor for retention.

During the first three months of 1983 IMPERVIOUS conducted training exercises and special operations in the Mayport area.  On 14 April she entered the Atlantic Marine Drydock at Fort George Island for a four month overhaul.  During this overhaul she was fitted with a new Raytheon surface-search radar to replace her aging SPS-53L system.  Upon her return to Mayport she conducted training exercises and special operations for the remainder of 1983.

In January 1984 she returned to drydock to correct a propulsion shaft problem.  She left drydock on 8 March for sea trials, and returned to Mayport on 10 March.  In April IMPERVIOUS participated as the MCM Command and Control Ship in Ocean Venture 84, a multi-service operational exercise simulating an amphibious landing on Vieques Island ,PR.  Port visits included Nassau, BI;  Roosevelt Roads, PR and Key West, FL.  She returned to Mayport on 9 May.  She returned to Charleston for a complete overhaul of her minesweeping generators and shipboard electrical systems.  She returned to Mayport in June.  On 15 July, 1984 IMPERVIOUS celebrated her 30th anniversary of commissioned service.  A ceremony commemorating this was held on 29 June.  Her original sponsor, Mary Lynne Moore Jackson was in attendance to recount the day she helped launch the ship.  In August the ship sailed up the St. Johns river for a two day port visit in downtown Jacksonville, FL.   She spent the remainder of 1984 conducting operations in preparation for an upcoming INSURV inspection, including leading the first breakout of Mayport-based ships through a simulated minefield during REDEX 2-84.  In January 1985 the Navy Board of Inspection and Survey cited IMPERVIOUS as "the most impressive of fifteen MSOs examined" during the previous year.

In early February 1985 she conducted special operations off of Mayport.  On 1 March the Mayport-based minesweepers of MINDIV 126 (which also included ENGAGE (MSO-433)  and EXULTANT (MSO-441) were re-assigned to the operational command of DESRON8 and CRUGRU12.  During March she also completed degaussing in Charleston before arriving in Savannah, GA on 17 March for the city's annual Saint Patrick's Day celebration.  IMPERVIOUS returned to Mayport in late March where she received all departmental awards in the 1984 Battle Efficiency competition.  She conducted training operations throughout the spring, culminating with a successful MRCI in June.  In late June she underwent self-radiated noise measurements in the Caribbean Sea.  During this time she towed a disabled Haitian fishing vessel into port and provided a vitally needed DC team to assist in combating a smoldering fire onboard the Mexican merchant vessel Puebla.  She made a port visit to Fort Lauderdale before returning to Mayport for sonar grooming and renovation in July.  In August she participated in another Mayport breakout during REDEX 3-85.  She ran the degaussing field in Charleston again in September, and conducted operations off of the Jacksonville coast throughout October.  In November she sailed to Fort Lauderdale to participate in special operations, then got underway to Charleston for a change-out of her magtail.

During operation Earnest Will (the re-flagging of Kuwaiti tankers) in 1987 to 1989 there were six MSOs deployed to the Persian Gulf.  A crew-rotation methodology was devised to relieve the crews after their tour was up.  The IMPERVIOUS herself was not deployed, but her crew took a turn.  On 21 August, 1988 the entire crew of the IMPERVIOUS was transferred to the ILLUSIVE in the Persian Gulf.   The ex-IMPERVIOUS crew became the ILLUSIVE's Gold Crew, while the ILLUSIVE's Silver Crew returned to the U.S. and took over the IMPERVIOUS.

In 1989 IMPERVIOUS deployed several times to the Caribbean as part of drug interdiction effort with the Coast Guard.  The ship underwent a Supply Management Inspection, for which they were awarded the blue Supply " E" for supply excellence, rarely seen in a minesweeper.  IMPERVIOUS also successfully completed an INSURV,  MCM/MTT basic and advanced inspections and an ORE given by Mine Warfare Inspection Group.  The culmination of the year's effort was the awarding of the Battle "E" for battle efficiency.  In mid-1989 IMPERVIOUS entered an extensive drydock and overhaul period in Charleston.  During this time she was forced to ride out Hurricane Hugo tied up to a pier unable to get underway.  Following the hurricane many IMPERVIOUS crewmen donated their time to relief and clean-up efforts in the Charleston area.

In the first week of July 1990 IMPERVIOUS sailed up the Potomac River to Washington D.C. for a liberty call before being deployed to the Persian Gulf for participation in Desert Shield/Desert Storm.  After the port visit in Washington, she sailed to Norfolk where she was loaded on the Dutch heavy-lift ship Super Servant 4 along with the ADROIT (MSO-506), LEADER (MSO-490) and AVENGER (MCM-1) for transit to the Persian Gulf.  At that time the crew was separated from the ship except a small detachment made up of selected crewmen from the four minesweepers to maintain the ships while transiting the Atlantic.   During the ship's transit,  the crew was sent to Charleston for firefighting training along with medical training for all hands.   The crew met the ship in Bahrain on 1 October for a short shake-down before commencing operations.   While deployed during Desert Storm IMPERVIOUS continually conducted mine exercises in conjunction with the other American sweeps as well as the British and Saudi Arabian Navies.

IMPERVIOUS was decommissioned 12 December 1991 and was stricken 18 March 1992. Sold for scrapping 15 April 1995, the purchaser defaulted and the contract for sale was cancelled 8 October 1996. We received confirmation in February 2002 that she was scrapped along with ENGAGE (MSO-433), EXULTANT (MSO-441), FORTIFY (MSO-446), AFFRAY (MSO-511) and  EXPLOIT (MSO-440)s.  The last of the U.S. MSOs are now gone.

Sources: USS IMPERVIOUS 30th Anniversary Book,  USS IMPERVIOUS Cruise Book 84-86, USS IMPERVIOUS Welcome Aboard Booklet,,  and certainly not least of all, Rick Szrypka's history as posted originally on the IMPERVIOUS' web site.  The 1966 account of the deployment to Viet Nam was contributed by Donald R. Blunt, a YN1 aboard her at the time.