Feb 1953: VP-21 replaced its P4M-1 Mercators with P2V-6 Neptunes, carrying the latest equipment for minelaying and ASW, a steerable nose wheel and reversible pitch propellers.
1 Aug 1958: The squadron’s primary mission was changed from aerial minelaying to antisubmarine warfare.
8 Jul 1958: VP-21 deployed to RNAS Halfar, Malta. During the deployment, the squadron participated in the Lebanon Incident from 15 July to 1 October 1958. VPs 21 and 10 provided ASW coverage to the Sixth Fleet during the crisis.
1 Jan 1967: Six VP-21 aircraft deployed to Rota, Spain, relieving VP-24. On 6 June to 23 June 1967, the Rota detachment deployed four aircraft to Souda Bay, Crete, for advanced base operations during the Arab-Israeli conflict.
21 Nov 1969: VP-21 was disestablished at NAS Brunswick, Maine.
Types assigned:
P2V-6 Feb 1953
P2V-5F Aug 1953
P2V-7S/SP-2H* Dec 1957
Major overseas deployments
| Date of departure | Date of Return | Wing | Base of Operations | Aircraft | Area of operations |
| Aug 1955 | Dec 1955 | FAW-3 | Malta | P2V-5F | Med |
| 8 Jul 1958 | 7 Dec 1958 | FAW-3 | Malta | P2V-7S | Med |
| 2 Mar 1959 | 10 Aug 1959 | FAW-3 | Sigonella | P2V-7S | Med |
| 2 Mar 1959 | 10 Aug 1959 | FAW-3 | Keflavik | P2V-7S | NorLant |
| 2 Mar 1960 | Aug 1960 | FAW-3 | Sigonella | P2V-7S | Med |
| 2 Mar 1960 | Aug 1960 | FAW-3 | Keflavik | P2V-7S | NorLant |
| 4 Jun 1961 | 6 Nov 1961 | FAW-3 | Argentia | P2V-7S | NorLant |
| 27 Oct 1962 | 26 Nov 1962 | FAW-3 | Lajes | SP-2H | NorLant |
| 27 Oct 1962 | 3 Dec 1962 | FAW-3 | Argentia | SP-2H | NorLant |
| 5 Jan 1963 | 1 Jun 1963 | FAW-3 | Sigonella | SP-2H | Med |
| 29 Apr 1963 | 1 Jun 1963 | FAW-3 | Souda Bay | SP-2H | Med |
| Apr 1964 | Jun 1964 | FAW-3 | Argentia | SP-2H | NorLant |
| May 1964 | Jun 1964 | FAW-3 | Guantanamo | SP-2H | Carib |
| 20 Aug 1965 | 1 Feb 1966 | FAW-3 | Rota | SP-2H | Med |
| 20 Aug 1965 | 1 Feb 1966 | FAW-3 | Keflavik | SP-2H | NorLant |
| 1 Apr 1966 | 18 Apr 1966 | FAW-3 | Bermuda | SP-2H | Lant |
| 1 Jan 1967 | 29 Jun 1967 | FAW-3 | Rota | SP-2H | Med |
| 6 Jun 1967 | 29 Jun 1967 | FAW-3 | Souda Bay | SP-2H | Med |
| 15 Oct 1967 | 15 Apr 1968 | FAW-3 | Sigonella | SP-2H | Med |
| 20 Feb 1969 | 26 Jun 1969 | FAW-3 | Sigonella | SP-2H | Med |