As others have, or will, point out, the Nimrod, as an ASW platform, worked largely out of sight of both the public and, we hoped, the potential enemy.
The submarine slipping silently steadily through UK waters was never that silent nor did it slip. Always a P3 or Nimrod or Atlantique was there sniffing his presence.
We flew a 365 day mission when most in the UK went about their normal Monday to Friday toil. Often we would work a normal week only for the weekend to be a hectic one with a continuous cycle of sorties. Sometimes we even continued south as far as the Azores.
If asked what we were doing the answer was always 'nothing', where were you going, 'nowhere'. When are you coming home, 'don't know.'