Atlantis reef is a section of the granite reef of the Castle Rocks restricted zone. The marine life has been protected for many years and is flourishing. For this reason please take extra care when diving this site so as not do damage the ecosystem.

Named by the first divers to report the dive site after the legendary lost continent of Atlantis, there are two massive pinnacles marking the site and known as the Pillars of Hercules, which rise to within 5m of the surface from the depths below.

The tops of the pinnacles are relatively small and rounded, and are probably in the order of 3m diameter, but they spread out to 15 to 20m wide with roughly rectangular plan at 12 to 15m depth.

The marine life is extensive and varied. At the tops of the pinnacles and extending to about 12m is a heavy covering of red bait with both knobbly and false plum anemones living in between them. Descending the pinnacles, the more delicate invertebrates take over and the pinnacles’ lower sections are densely covered with bryozoans of at least five different species,

and a heavy covering of multicoloured seafans. Between the pinnacles is usually found a school of several species of fishes: blacktails, hottentots, fransmadam and zebras. Moderate numbers of bank steenbras have been seen on the western part of the reef. Nudibranchs such as the black, the crowned and gasflames are common on the pinnacles, with the occasional sighting of smaller nudis such as the orange-eyed nudi and the white-edged nudi. Janbruins can often be seen in the cracks between the pinnacles, and there are some very large Roman.

Where the reef at the base of the pinnacles meets the sand to the south, the lower parts of the reef are covered with red-chested sea cucumbers, strawberry anemones and nippled sea fans. North from the pinnacles in the jumbled boulders is a luxuriant seafan forest, consisting of palmate, sinuous and whip seafans. The usual assortment of invertebrates associated with seafans can also be found: topshell snails, hermit crabs and basket stars in abundance. Further north on a lower profile reef section there is more seafan forest which is sometimes overwhelmed by hairy brittlestars to the extent that it resembles an afghan rug. The sand at about 29m seems to be a shyshark nursery because many small puffadder shysharks can be seen there. Interestingly, the site also features an unusual number of dark shysharks, more usually seen on the Atlantic side of the peninsula.


Maximum depth: 29m

Average Depth: 20m

Visibility: 4-10m depending on prevailing weather conditions


This site is within a Marine Protected Area and a permit is required to dive the site.