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The dive sites at Windmill Offshore Reefs are offshore rocky reefs in the Seaforth area of False Bay, near Cape Town in the Western Cape province of South Africa.

Understand[edit]

Map of Windmill Beach and the offshore reefs.
Detail map of Dangerous Doug Reef

These are several scattered groups of granite outcrops between about 400 m and 1.5 km offshore of the well-known shore entry site at Windmill Beach. These offshore reefs are seldom dived and little known. Some may never have been dived. Most have not yet been surveyed, and do not feature on the official navy hydrographic charts. The approximate positions without any depth detail were taken from a sidescan sonar survey by the Council for Geoscience, and they are gradually being explored and mapped. Those which have been partly surveyed are Outer Windmill, Dangerous Doug Reef, Windmill Offshore, Lace Reef and the Three Bears Pinnacle. SUEX Reef was first visited on a shore dive with scooters from Windmill Beach East Cove. The position was estimated by dead reckoning and allocated to the most likely looking reef in the area. The reef identity is yet to be confirmed by GPS, or surveyed.

Position[edit]

  • 1 Three Bears Pinnacle: S34°11.887' E18°27,788'
  • 2 Dangerous Doug Reef: S34°11.950' E18°27,650'
  • 3 Lace Reef: S34°11.960' E18°28,125'
  • 4 Windmill Offshore: S34°12.050' E18°27,800'
  • 5 Outer Windmill: S34°12.090' E18°27,610'
  • 6 SUEX Reef: S34°12.140' E18°27,885' (estimated, possibly E18°27,800')

This area is in a Marine Protected Area (2004). A permit is required. Some of the sites are inside the Boulders Restricted Zone.

Name[edit]

  • Windmill Offshore Reefs describes the geographical location offshore of the local landmark, Windmill Beach, as do the names Outer Windmill and Windmill Offshore. If there ever was a windmill, it is lost to memory.
  • Lace Reef was named for the large numbers of lacy false corals (bryozoans) seen at the reef.
  • Dangerous Doug reef was named for a local diver who did a shore dive to Photographer's Reef, and for the return swim, made the error of using the same course he had used to get to the reef, eventually surfacing quite far out to sea, possibly in the general vicinity of this reef, and was picked up by a passing boat.
  • Three Bears Pinnacle has three outcrops; one large, one small, and one in between in a tight little clump.
  • SUEX Reef.

Depth[edit]

  • Dangerous Doug reef: The high points is at about 12m, towards the northwest, and maximum depth somewhere in the vicinity of 20m, to the east of the reef
  • Lace Reef: The maximum depth is about 30 m at Lace Reef, the furthest offshore of the group, shallow point about 23&nbso;m
  • Windmill Offshore: The top of the pinnacle is at about 18m, and the sand bottom is about 27 m
  • Outer Windmill: The shallowest point is at about 7 m, and the sand bottom is at about 12 m
  • SUEX Reef: Estimated between 14 and 21 m deep

Topography[edit]

The reefs are likely to be all granite corestone outcrops with occasional boulders. The reefs vary considerably from clusters of moderately sized outcrops to massive lumps of rock, much like other reefs of the area.

  • Dangerous Doug reef: Medium profile granite reef with occasional areas of higher and lower profile. Eastern part includes large area of fairly level lower profile reeftop. West end is a cluster of relatively high outcrops with sandy bottomed gullies between them. There are a few low outliers to the northeast, and a group of outcrops to the north known as Dangerous Doug North Reef, from a bit below 15 m on the sand to about 10 m at the top.
  • Lace Reef: Top of reef at about 23 m. Reeftop mostly quite flat, and some areas very flat. Reef edge drops off from about 27m to 32m. Most of the edge fairly steep with a 3 to 5 m drop, bur some flat areas with a little bit of broken reef. Large area of exposed granite bedrock. Fairly flat on top, several long straight gullies with sand bottom.
  • Windmill Offshore: Maximum depth recorded about 27 m on sand, top of reef about 18 m. Granite outcrop with deep sandy bottomed gullies and indentations and a few high points. A couple of small outliers to the northwest.
  • Outer Windmill: Sand bottom at about 12 m, top of reef at about 6.5 m. Not much relief.
  • Three Bears Pinnacle: A tall almost vertical sided pinnacle rising from the sand at 27 m to peak at 17.5 m, with a narrow crack separating it from the lower pinnacle at about 22 m on top, and the third outcrop which is even lower.
  • SUEX Reef: a long, narrow pair of straight parallel ridges with a narrow strip of sand between them. Not very high, but with a couple of higher boulders or outcrops. Fairly unmistakable appearance. Position unconfirmed but almost certainly one of the reefs labeled. Top of reef at about 14 m, sand at about 21 m.

Precambrian granite of the Peninsula pluton, surrounded by fine quartz sand and patches of shelly sand and gravel.

Conditions[edit]

Get in[edit]

Windmill Offshore Reefs and nearby dive sites

Usual access is by boat from Simon's Town or Miller's Point. It would be possible for a fit diver to do some of these reefs as shore dives from Windmill Beach, but the route is across the path of small craft and there would be a risk of being run down while at the surface.

The site is about (distance) km from the Miller's Point slipway, or (distance) km from Simon's Town jetty

See[edit]

Marine life[edit]

Dangerous Doug reef:

Lace Reef:

Notable for the large numbers of pristine lacy false corals (Retoporella lata?), for which the reef was named. Numerous juvenile puffadder shy sharks have been seen, and there is heavy cover of hairy brittle stars in places on top of the reef. Mauve sea cucumbers are common, and a few varieties of sponge, palmate and sinuous sea fans. Sea spiders (pycnogonids) and spider crabs have also been seen,

Windmill Offshore:

Three Bears Pinnacle:

A compact and rather small reef, which feels a little crowded with more than 6 divers, as it is only about 20 m in diameter. At the time of survey there were a few small sea fans, and the dominant group was echinoderms. Lots of mauve sea cucumbers, elegant feather stars and fragile brittlestars.

Photography[edit]

Suggested routes[edit]

The sites are not well known and there are no recommended routes.

Stay safe[edit]

Hazards[edit]

The area is crossed by small boat traffic from the False Bay Yacht Club at Simon's Town, and from the town jetty.

Skills[edit]

No special skills are required, other than those appropriate to the depth of the dive, Several of the sites are in the depth range appropriate for entry level divers, and the rest are within the normal recreational diving depth range.

Equipment[edit]

A DSMB is recommended if you are likely to surface away from the shotline, as a way for the boat crew to find you, and for other boats to be warned of your presence at or just below the surface.

Nearby[edit]

Back to Diving the Cape Peninsula and False Bay#Seaforth to Froggy Pond

This dive guide to Windmill Offshore Reefs is a usable article. It has information on location and equipment as well as some complete entries on what to see. An adventurous person could use this article, but please feel free to improve it by editing the page.