The 22 is the Beaver, commissioned 18 Dec 1984, so the photo was taken 1985 onwards. Suspect it could be the PR shot for a new passive sonar that then had just come on line. At the time was serving in the RMAS St Margarets which was then heavily involved in sonar trial plus towed array trials due to her having steam recip engines which made her as quite as the O/P class subs in quite running routine.
In 1984 we had just finished trials with a system which we called the spider, it was a 30ft diameter ali rig with about 30 hydro phones on it. The thing was put over the side and was suspended from a large buoy with bungee cord. We then steamed backwards and forwards upto 1.75 miles and .25 miles from it for days. The position was 200 miles south of Madeira, the best thing was we had an endurance of 10 days so we had 2/3 runs into Madeira for bunkers. This rig was so sensitive it could pick up ships leaving New York, the big problem was identifying sea noises like whales and calibrating for them. The chief scientist told me that the real problem was shrinking it all to fit into a passive sonar buoy to be dropped from a he-lo. Although the Pict shows I believe another expensive British weapon flop the stingray, after several billion pounds spent on R/D no one would buy it , so it was foisted onto the RN. The trouble with it I believe is that any nuc sub can outrun when submerged.