Diving the Cape Peninsula and False Bay/Tivoli Pinnacles
This site is part of the Roman Rock reef complex, and is convenient for launches from Simon's Town. The site is fairly small and has interesting topography, and a good variety of the local invertebrates and fish.
The name "Tivoli Pinnacle" is derived from the town of Tivoli, Italy which is a short distance east of Rome, as this pinnacle is a short distance to the east of Roman Rock.
Maximum depth is about 22m on the sand to the south, and the top of the pinnacle is at about 10m.
This site is a fair distance offshore, and is not much affected by breaking waves, so the visibility will generally be as good as any other site in west False Bay, and better than the inshore sites. Visibility can be in excess of 15m on a very good day, but is more likely to be in the 6 to 10m range.
The reef is relatively long and narrow with the long axis running roughly North-South (330° magnetic). Length is about 190m, and width about 60m. There are other extensive reefs of similar topography, geology and ecology nearby, at Roman Rock to the west, Castor Rock to the north, Rambler Rock to the east and south east and some unnamed pinnacles to the north east.
The reef has a high profile pinnacle group towards the south end, and another, much smaller and slightly lower group to the far north. The area around the south pinnacles and as far as the north pinnacles, appears to be mostly low profile corestone bedrock and boulders, with much of the perimeter quite broken, particularly on the west side. There are a few outliers, some of which appear to be quite extensive, but most are low and small. The southern sector of Castor Rock reef is visible from the northern extreme in good visibility, across about 10m of sand.
The main pinnacle of the southern group has a fairly flat top between about 10 and 12m depth, and there is a much smaller pinnacle a few metres to the east.
The surrounding sand is at about 21m to the south, gradualy rising to 18m at the far north and north west. Pinnacles to the south are mostly bedrock outcrops, wall sided in several places, and fairly flat topped, with a number of lower parallel ridges and gullies running roughly parallel to the long axis of the reef. The northern pinnacles are mostly large boulders standing on low bedrock, with near horizontal jointing about 1 to 2m from the bottom. The tops of these pinnacles are estimated to be deeper than 12m.
Geology: Pre-Cambrian granite of the Peninsula pluton. Corestone outcrops and boulders with jointing predominantly roughly north-south, some large, and surrounded by fine white quartz sand.
The site is exposed to wind and waves from the south east, so should be dived when the prevailing swell and wind is westerly to at least some extent, or, of coure, when it is calm. The site is reasonably protected from south westerly swells, but if the wave period is long (13 seconds or more), a significant part of the swell will make it round Cape Point, and the surge may be uncomfortable and visibility reduced.
The site is usually at it's best in winter but there are also occasional opportunities in other seasons.
This site is always dived from a boat, as it is too far offshore to swim and is in the harbour approached of the Simon's Town Naval harbour. The site is about (distance)km from Miller's Point slipway, or (distance)km from the pickup point at Long Beach
The north pinnacles are notable for large Bank Steenbras, which have been seen in groups of up to 4. The south pinnacle has several large Roman in residence. The steeper sides of the pinnacles are encrusted with large numbers of feather stars, and there are good examples of gorgonian sea fans in the deeper parts. The more horizontal areas often have large groups of grey sea cucumbers clustered so closely that the reef can't be seen between them. Thera are large red-bait pods in the shallower ateas, and other places have large numbers of strawberry anemones.
Macro equipment will usually give some good results, as there are vast numbers of small invertebrates, and wide angle lenses may capture the rugged topography if the water is sufficiently clear. The reef is shallow enough that lighting can be quite good, but it is at the same time too deep to retain much red or orange, so colours will be muted and greenish unless artificial lighting is used. For distances over about 300mm, this is best done with external stobes, to minimise backscatter.
No specific routes are recommended. Diving near the pinnacle is likely to provide the most interesting sea life and scenery, but a short visit to the sand will provide a bit more variety. Boats will usually put down a shotline at the south pinnacle, and it will normally be convenient to start and finish the dive at this point. The site is not particularly deep, and there may be time to visit the north pinnacles, and hope to see a few Bank steenbras.
No site-specific hazards are known.
No special skills are required. Most of the site is in the depth range suitable for entry level divers, and the deepest parts are anly a few metres deeper.
No special equipment is required. If you plan to surface away from the shotline, a DSMB is recommended.