A submarine is considered the stealthiest offensive element of a naval force. Pakistan Navy was the first in the Indian Ocean to raise a submarine force in 1964. The first submarine PNS/M GHAZI (Ex-USS DIABLO) acquired from the US in June 1964, proved its mettle shortly afterward in the 1965 war when the entire Indian Navy remained bottled up in ports due to the deterrence created by PNS/M GHAZI.
Subsequently, Pak Navy modernized its submarine force by inducting three Daphne Class French-built submarines. These were commissioned as HANGOR, SHUSHUK, and MANGRO on 1 Dec 1969, 12 Jan 1970, and 5 Aug 1970 respectively. These units played a vital role in the 1971 war and PNS/M HANGOR had the distinctive honor of sinking INS KHUKRI and seriously damaging INS KIRPAN astride Kathiawar coast. The HANGOR is the 1st conventional S/M of the world to score successful hits against surface units in combat since World War II.PN Submarine Force also takes pride in operating 3 X-Craft (small submarines) this has enhanced the number of sub-surface units.