Difference between revisions of "Diving the Cape Peninsula and False Bay/Maidstone Rock"
Latest revision as of 16:40, 29 June 2012
The dive sites Maidstone Rock Maidstone Reef and Ammo Reef are offshore rocky reefs in the Seaforth area of Simon's Town on the False Bay coast of the Cape Peninsula, near Cape Town in the Western Cape province of South Africa.
This site is in a Marine Protected Area (2004). A permit is required. The site is entirely inside the Boulders Restricted Zone.
"Maidstone Rock"is the name given the to the high pinnacles of the reef on the SA Navy charts. The deeper but more extensive reef to the east is known as Anchor Reef, and the scattered outcrops around the two are generally referred to as the Maidstone Rocks.
Ammo Reef is the compact reef further to the east. Several large naval gun shells have been seen on the reef.
Maximum depth is about 21m on the sand at Maidstone Rock, and the top of the highest pinnacle is about 7m deep at low tide.
Maximum depth at Anchor Reef is about 24m on the sand, and the highest point is about 10m deep.
Ammo Reef is about 17m on top, and the surrounding sand is about 27m deep.
The reefs include a cluster of granite pinnacles of various heights on a flat fine sand bottom, and a large contiguous section of reef of about 226m east to west by 113m north to south, rising about 15m from the sand at the highest point, but mostly somewhat lower. About 100m further east across the sand bottom, a substantial outcrop known as Ammo reef rises from 27m on the sand to 17m on top, with several parallel cracks running roughly east-west.
Maidstone Rock is the highest of a dense cluster of very precipitous granite pinnacles on fairly flat sand bottom. The site is spectacular in good viz. The main cluster is quite tightly packed, with the pinnacle ridges running more or less north east to south west, and gaps of a few metres wide between them. There are probably more pinnacles to the east and to the north west but these have not yet been surveyed. A couple of the pinnacles have deep rounded undercuts part way up the sides, but not quite enough to trap air.
Anchor Reef is a large, fairly flat topped area of bedrock that extends a few metres above the sand. Sand bottom at the edge of reef ranges from about 21 m to 24m near the rock, but to the north the sand slopes down visibly past a few outliers and reaches 26m quite nearby, at which stage it has flattened out. The central north side seems to have nore rugged topography, with a steep drop-off from above 18m to the sand. The profile is steep and high along the north side, but flatter in most places, and there are a large number of small boulders scattered along the slopes to the south. There is a large anchor lying on the reef just below 18m to the south, and this section of reef is named for the anchor.
Ammo Reef to the east of Maidstone reef is a fairly monolithic outcrop with a marked groove along the length of top, and parallel jointing to the north east. The top of reef is about 17m deep, and the sand bottom at about 27m to the east. The topography is not particularly rugged, and most of the reef edge slopes fairly gently down to the sand. A few fairly large bore naval shells have been seen on the reeftop. They appear to be about 125mm diameter, but are quite heavily encrusted.
Geology: Late Pre-Cambrian granite from the Peninsula pluton. Some of the pinnacles of the Maidstone Rock group have the characteristic rounded edges and corners of corestones, and the rounded undercuts in the tall pinnacles suggest that they were originally weathered underground. The Anchor Reef and Ammo Reef outcrops have the typical rounded shape of corestones, and there is a large amount of relatively small boulder-rubble along the southern perimeter of Maidstone reef.
The site is exposed to wind and waves from the south east, so should be dived in westerly winds or a calm. The fetch is long enough for a north-westerly wind to develop a lumpy chop, but not long enough for this chop to reach down to the reef, though the ride may be wet and bumpy.
The site is reasonably protected from south westerly swells, but long period swells from the south west will cause strong surge, and may reduce visibility
The site should usually be at it's best in winter but there may also be occasional opportunities at other times of the year.
Access to this site is by boat, It is about 4.4km from the Miller's Point slipway to Maidstone Rock, and much the same to Anchor and Ammo Reefs.
Alternative boat access from the False Bay Yacht Club is closer, at about 3.4km to Maidstone Rock and 3.8mkm to Ammo Reef.
The distance from Long Beach is slightly less.
Typical of the outer reefs in this area, but not many sea fans. Different rocks have different characters with different dominant invertebrates. Mauve sea cucumbers, striped anemones, strawberry anemones, black brittle stars and common feather stars are abundant. Large numbers of large whelks with egg masses have been seen. Fish may include Roman and small shoals of Hottentot.
There is a large iron Royal Navy style anchor about 6m long, 4m wide on top of Maidstone Reef just below the 18m contour to the south. The anchor has lost its stock and one fluke is broken, but still with the anchor. The crown is a slightly pointed curve, the flukes large and triangular, each about a metre long. The shank is about 6m long, lying roughly horizontal about half a metre above the reef. The ring is large, about 600mm diameter, suitable for use with thick natural fibre cable. There is no sign of a hole in the shank for an iron stock, so it may have had a wooden stock, as was common on older anchors of this type.
Macro or wide angle lenses are most suited to the site and the visibility to be expected.
Maidstone Rock: — No particular routes are known. Work your way along the line of pinnacle as suits you best. The high pinnacles are clustered together and this is the most spectacular part of the reef, both for topography and diversity of life.
Anchor Reef — There are two areas of interest: The old anchor, and the north face. The anchor is relativelt small and difficult to find, so start there. When you have seen enough, swim north to northeast and you will get to the highest point. Further north the reef drops down to the sand quite rapidly, and there are a few scattered outcrops on the sand slope. The wall of the north face is steep and quite complex, so it will have the highest diversity.
Ammo Reef — This is a compact reef, and you can visit most of it on a single dive. There is not a lot of variation in topography in different directions, so go where it pleases you. There are a few naval artillery shells lying on the slopes, but they are quite small and not particularly interesting, so not worth a search. Start deep and work your way up is as good a plan as any.
No site specific hazards are known.
No special skills required. Ability to deploy a DSMB recommended.
The depth is a bit much for entry level divers restricted to 18m, and although much of the Maidstone Rocks pinnacles is above 18m, the walls are near vertical, and the bottom is consistently deeper than 18m, so good buoyancy control is needed to stay above 18m.
No special equipment required. A DSMB is recommended to inform the boat of where you will be surfacing.