Whittle Rock

Whittle Rock’s Anchors

 There are several ancient anchors scattered over the reef. Some of these are possibly associated with ships going aground or even wrecking on the shallow pinnacle. H.M.S. Trident reportedly struck Whittle Rock in 1796. In 1810 the British East Indiaman Euphrates also struck the rock, but it got off and was repaired, only to be wrecked off Ceylon in 1813. Four large Admiralty Pattern iron anchors, lying in close proximity to each other have been attributed to this ship. It is also likely that a number of the anchors remain from historic buoys that have marked Whittle Rock as a shipping hazard since the early 1800’s. Artifacts known as “Neptune’s Bathplug” and “Victor’s chain” are possibly the moorings from such historical buoys. There are also several smaller anchors, and these could have been lost by fishing vessels that would have operated on the reef system in years gone by.

The positions of 15 anchors are known and listed in a table below.

Kelly Graham on Kelly’s Anchor

Mapping Whittle Rock

In 1797 Rear-Admiral Thomas Pringle ordered H.M. Brig Euphrosyne to chart this area of the bay and to find the dangerous rock. Lieutenant Daniel Whittle, commander of the Euphrosyne, reportedly found the rock, that would later bear his name, in January of that year and placed the first buoy there to warn mariners of its danger. The rock appears on a 1797 Dutch chart as Witte Rots. Whittle Rock and some surrounding reef appears on today’s SAN charts.

Peter Southwood of SURG Maps started detailed mapping of Whittle Rock in 2014, using his own established contour mapping technique of towing a surface float with a GPS track recorder, while swimming contours at 3 m depth intervals. From 2018 Wreckless Marine collaborated with Southwood in locating new sites and sharing information. By the time Wreckless Marine conducted its first multibeam survey of the reef system in 2022, Southwood had made remarkable progress in mapping most reef system in 3m contours down to a depth of 30m. Details of this work can be found at the link below:

https://en.wikivoyage.org/wiki/Diving_the_Cape_Peninsula_and_False_Bay/Whittle_Rock

The 2022 Wreckless Marine multibeam survey provided detailed bathymetric data of the entire reef system and its surrounds and identified a number of new dive sites. The reef was surveyed again in 2025 in ultra-high density, enabling the generation of high-resolution maps of the reef.

Topography and Geology of Whittle

The reef at Whittle Rock is characterised by a series of parallel. ridges, primarily running northwest to southeast, intersected by secondary jointing that forms narrow, deep gullies running predominantly north to south.  Whittle Rock is formed from outcrops of Peninsula Granite, a large batholith that was intruded into the sedimentary Malmesbury Group about 630 million years ago. This granite crystallised deep in the earth and has since been exposed through prolonged erosion.

The reef can be described as a large granite tor, rising abruptly from the surrounding flat and sandy seafloor, with steep, craggy features interspersed with flatter areas and occasional sand-filled depressions. The granite boulders have a characteristic spheroidal shape as a result of preferential weathering along intersecting fractures. The rock is coarse grained, with pink or white feldspar crystals, glassy brown quartz and flakes of black mica. During the most recent ice ages, sea levels in this region were significantly lower, meaning the reef was exposed above sea level, and much of its detailed topography was probably shaped during this period.

Sediment around the reef varies, with rubble, gravel, pebbles and shells mainly occurring along the reef edges particularly to the north. The surrounding seabed is predominantly composed of fine sand at depths of approximately 30 to 42 m. Sand also accumulates in local depressions across the reef, often with a relatively high shell content.

To the east of the main shallow reef, the seabed deepens rapidly over a short distance, forming a steep and craggy terrain with several prominent outlying reef features separated by a narrow sand gap. The main reef generally slopes down toward the southwest, where it transitions into a long, narrow sand tongue that extends and slopes down toward the southeast.

Sea fan on Whittle Rock reef

Whittle Maps

Whittle Anchors

Download PDF

3D IMAGES

Dive Sites

Anchors

Photo Gallery

Short-tail stingray

Riaan’s Anchor

Acknowledgements

• Wreckless Marine Survey Team: Bruce Henderson, Ben Henderson, Grant Whitford.

• Peter Southwood and Gigi Birkett – Whittle Rock write up.

• Tanya Cilliers – Map work and 3D models

• Victor Oblom and Bruce Henderson – Photos