Diving the Cape Peninsula and False Bay/T.S. McEwan

The dive site T.S McEwan or Smoky Sue is an offshore recent wreck in Table Bay area on the west coast of Cape Town in the Western Cape province of South Africa.

The steam tug T.S. McEwan was well known in Table Bay harbour for many years. At the time of its construction in 1925 at Paisley, Renfrewshire, Scotland, it was said to be the most powerful tug in the world, and it provided a long service to shipping in Cape Towm from 1925 of some 50 years, including salvage operations. Length 48.72 m, beam 10.55 m, 793 tons, powered by two triple expansion steam engines driving two shafts, each with two water tube boilers, giving 2800 hp, for a maximum speed of 13 knots and a bollard thrust of 30 tons. After 50 years of service it was scuttled in Table Bay.

-33.86273318.2694331 T.S. McEwan (Smoky Sue): S33°51.764' E018°16.166', 11.1km SW of Robben Island lighthouse. This site is in the Robben Island Marine Protected Area since 2019. A permit is required.

The tug was named for T.S. McEwan, who was the general manager of Cape Railways from 1902 to 1920. The nickname Smoky Sue referred to the large amounts of black smoke it tended to emit.

Maximum depth of the site is about 82 m. and the top of the shallowest point on the wreckage is about 75 m.

Visibility at the wreck is not very predictable based on surface conditions, but turbid surface waters predict very low light levels at depth.

The wreck lies roughly upright on a rocky bottom, with a slight list to starboard, and has broken up considerably. The centreline lies at 133°T, with the bow to the southeast. The superstructure and deck have mostly wasted away, but the boilers and engines are fairly intact.

Geology: Precambrian sedimentary rock of the Tygerberg formation.

The site is exposed to all winds and swells with a westerly component, so should be dived in calm or light offshore winds and low swell, and may be good after a southeaster. The depth limits the effect of surface waves on the wreck, but conditions during the ascent and visibility of divers at the surface should be taken into account. South-easterly winds may be strong on the south peninsula but light over Table Bay.

The site is likely to be at its best in summer but there may be opportunities at other times of the year. This is an area which sometimes has upwellings caused by south-easterly winds, but it is not as strongly affected as some other parts of the Cape Peninsula. Sunny days in summer will generally cause plankton bloom to close down surface visibility, but under the bloom it may be relatively clean but can be very dark.

The site is exposed to wind and wavaes fron the northeast and southeast, so should be dived in calm or moderate southeasterly weather and sea conditions, but if a strong southeaster is forecast it would be prudent to avoid diving as considerable decompression would be needed from the depth of the wreck.

Boat access only. The site is a long way offshore. Boats will usually leave from the Offshore Powerboat Club at Granger Bay, or from the V&A Waterfront.

The only known reason to dive at this site is to see the wreckage of a well-known feature of mid 20th century Cape Town harbour.

Wreckage of a large twin screw steam powered tug of the early 20th century, somewhat broken up.

The site is deep by technical diving standards, and requires bottom gas mixture which will not support consciousness et the surface, and multiple decompression mixtures. It is also in the approached to a major international port, so large ship traffic ma be expected. Long decompression times will be complicated by low water temperatures. Strong offshore winds may develop during the periods when best underwater conditions are likely, but forecasts are usually reliable.

Competence at advanced trimix diver level is necessary as a minimum.

The depth of the site makes hypoxic trimix necessary for the bottom sector, putting this squarely in the realm of advanced trimix technical diving. Either open circuit with multiple decompression gases, or rebreather equipment is necessary.

• Bruce Henderson and Kelly Graham, 2024, Wood, Iron and Steel: Shipwrecks Mapped off the Western Cape, Wreckless Marine, Cape Town. ISBN 978-1-037-00702-6 for high resolution sonar images and photos of the vessels, and more details of their working history.

• -33.8245518.4710171 MV Seli 1
• -33.83143318.3587332 Robben Island steamer wreck Gilia
• -33.835218.3809673 Whale Rock
• -33.83518.3816674 SS Hypatia
• -33.8398618.385565 MV Daeyang Family
• -33.873318.316356 Disa
• -33.873118.3249177 Mooivlei
• -33.87473318.3454838 Blomvlei
• -33.8818318.3385839 MV Gemsbok
• -33.88596718.430510 Highfields
• -33.88778318.36581711 King Emperor
• -33.89666718.39666712 SS SA Seafarer
• -33.897518.409513 RMS Athens
• -33.90618.397514 Three Anchor Bay
• -33.90793318.417915 Two Oceans Aquarium
• -33.91508318.35701716 Sea Point Ridge Pinnacles
• -33.92618.377517 Bantry Bay
• -33.930918.3641518 North Lion’s Paw Main Reef

Back to the Alphabetical list of sites, or list of dive sites of Table Bay and approaches

Other regional dive sites:

• Dive sites of the Cape Peninsula west coast
• Dive sites of the Cape Peninsula east coast
• Dive sites of False Bay offshore and approaches
• Dive sites of False Bay east coast
• Fresh water dive sites of the Cape Town Metropolitan Area