If entering from the ramp, head south with the reef on your left. In about 8 metres depth, the reef will begin to swing around to the left and here you have the option of continuing along the sand line (much longer), or cutting east across the boulders. Swimming through the boulders at around the 12 metre mark due south of the point will bring you to the above-mentioned caves. They can be easily missed, so look out for a defined crevasse through the rock, which leads straight into the Cathedral. After exploring the caves, consider turnaround if you've entered from the ramp.
If entering from the point, head due east for about 50 metres or so and you should be directly on top of the caves. This entry also gives you the opportunity to explore the site the north of the point, where you can achieve up to 20 metres in depth.
After an entry from the midway point, swim away from the point for approximately 30 meters and then descend onto the boulders, in 6-8 meters of water. Take a 120 degree bearing and you will be inline with the caves (about 100 metres away).