The Shack was supporting a joint maritime/air defence exercise involving Buccaneers from 12 Sqn firing TV Martel missiles at smoke floats which had been dropped by the unfortunate Shack. Once the smoke floats were in the water a Nimrod VASTAC'd the Buccs onto the target for the live firing.
All at the same time the F3's were tracking the martels to see if was possible or even likely that a cruise missle target could be engaged by the F3 system.
It's not a coincidence that the Martels were being replaced by Sea Eagles at the same time as the exercise. It had been deemed that it was cheaper to fire them off into the Atlantic than to have them broken up and the nasty bits disposed of in an environmentally friendly way.
I was on 12 at the time waiting for my QWI course to start, a very sad end to a jolly good jape! We lost some good lads on that one.