Rocky Bank

Understand

This site has a different ambience to other Cape Peninsula and False Bay sites, and may have better visibility much of the time. The reef is spectacularly colourful in artificial light, and may have better visibility over a wider range of surface conditions, but has not been dived enough to be reliably predictable. It is a long boat ride, and the risk of getting lost at sea in rough conditions may not be acceptable.

Position 1 Rocky Bank: S34°24.93' E18°35.50' (arbitrary nominal position) This site is not in a Marine Protected Area (2004). A permit is not required.

Name

The name "Rocky Bank" is recorded on the SA Navy charts of the area. It is also a simple description of the area which is a bank of hard sandstone, mostly between 25 and 30 m deep on top.

Depth The top of the bank is at about 22 m. The chart suggests that the area shallower than 30 m is about 2 square kilometres, and it slopes down gradually to over 100 m to the south. Most dives reported have been in the 25 to 30 m depth range. It has been difficult to find shallower areas due to the general flatness of the bottom.

Visibility The bank has not been dived extensively, but there are indications that the visibility is usually better than average for the False Bay region, as the bottom is rocky, there can be a current, and the water is fairly deep and quite far from the coast, so waves will not easily disturb any sediment, and the current would carry it away rapidly. Visibility has been reported at between 10 and 20 m at the bottom. Algal blooms may reduce visibility near the surface to less than 5 m. Visibility can be good to excellent (over 15 m) on days when the inshore dive sites are murky, and even Whittle Rock is mediocre. Possibly the Cape Town dive site with the most consistently good visibility.

Topography This is a large area, and probably varies considerably from place to place. Reports indicate that a large area is moderately flat hard sandstone reef with low dip angle, so the

Getting there

This site is only accessible by boat. It is about 24 km from Miller's Point slipway, 31km from Simon's Town Jetty,or 37 km from Gordon's Bay Old Harbour.

See

Marine life

The rocks are encrusted with a large range of colourful sponges, ascidians, soft corals, noble corals, hydroids, and coralline algae. Shoals of small fish, and larger yellowtail swim over the reef, and occasionally sharks will be seen. The reef has more the feel of a South Coast reef than a False Bay reef, because the invertebrate assemblages have a different character. The character of the reef life varies with depth and reef profile, but this has not been reliably analysed in detail.

Photography If the visibility is good, almost any equipment should produce good results. Natural light will be blue or green due to the depth, so a strobe or other artificial light will be needed to bring out the bright reds, oranges, and yellows.

Do

Dive at one of the drop points listed and explore the vicinity, or choose another point and see what you find. Most of the reef is unexplored, and though most of it has been surveyed by multibeam sonar, the images have not yet been published. The listed points indicate depth at the point. Depth does not usually vary much within a reasonable distance as the reef is not very steep overall and profile is moderate to low in most places. 1 22m drop: S34°24.820’ E018°35.473’ 2 25m drop: S34°24.906’ E018°35.478’ 3 30m drop: S34°24.957’ E018°35.473’ 4 Gully: S34°24.586?’ E018°35.189’, a long shallow east-west depression the runs right across the bank with a minimum depth of about 32m in the middle, with slightly shallower low profile reef to the north and south. Rather surprisingly there is a fairly large patch of sand in the middle, near the top. The drop mark is at the sand patch. 5 32m drop: S34°24.994’ E018°35.463’ 6 36m Pablo's Steps: S34°25.126’ E018°35.756’. Drop onto about 36m and travel northwest up a series of low steps. 7 40 to 50m Rocky Ridge: S34°24.941’ E018°36.512’, A long east–west gnarly drop-off about 5 to 8 m high, with heavy encrustation of noble corals and sponges on the wall. More a step than a ridge, as it only drops off on one side. About 40 m deep on top of the ridge and about 45 m on the bottom, maximum depth about 50 m. 8 45m Ahmed's Bluff: S34°25.392’ E018°35.841’, a low bluff structure at about 45m, dropping off to about 50m. 9 50m North East Buttress: S34°23.842' E018°36.829’, a magnificent buttress about 45m on top dropping off steeply to 60 m Big walls, overhangs and lots of noble coral.

Routes The site is vast and large areas are not distinguished by any notable features. No routes are known yet – find a place of suitable depth and do a drift dive.