The site is quite shallow until you reach the sandy floor, with scattered boulders and stands of kelp the encountered terrain. Head due north from the entry to reach the shark cave. At the end of a large section of kelp you'll find the wall and the mouth of the cave. The cave is approximately 5m/15ft deep and 1.5m/5ft high. At what appears to be the end of the cave is a small opening - here the cave recreates its outer dimensions and it's here the sharks dwell. Lure them out with frozen pilchards and patience, be prepared to use up to ten minutes of air and take a torch!
Heading east along the wall for approximately 50 metres will bring you to quite a long zigzagged swimthrough. This can also be found by heading northeast from the entry point to a large boulder flanked by two smaller rocks amongst which is a long iron bar. This bar points in the direction of the swimthough, which is another 20 metres or so northeast.