Difference between revisions of "Diving the Cape Peninsula and False Bay/Noah's Ark"
Revision as of 09:19, 22 March 2011
The dive sites Noah's Ark and the Ark Rock Wrecks are rocky reef and historical wreck sites in the Seaforth area on the False Bay side of the Cape Peninsula, near Cape Town in the Western Cape province of South Africa.
These are minor wrecks of some historical interest and a large exposed rock surrounded by a small high profile reef. There are also a few isolated groups of rocks and structures that were part of a now disused naval degaussing range.
Noah’s Ark: S34°11.533’ E018°27.232’
Ark Rock Barge wreck: S34°11.603’ E018°27.198’
Boiler wreck #1: S34°11.545’ E018°27.173’
Boiler wreck #2: S34°11.670' E018°27.196'
Boiler wreck #3a S34°11.632' E18°27.349'
Boiler wreck#3b S34°11.616' E018°27.353'
Parana wreck, (1862): S34°11.477’ E018°27.172’ (main section)
Double row of concrete pillars: S34°11.618' E18°27.277'
Single row of concrete pillars: S34°11.649' E18°27.220'
Eastern wreck: S34°11.530' E018°27.306'
Heat exchanger?: S34°11.566' E18°27.287'
These sites are in a Marine Protected Area (2004). A permit is required. These sites are all entirely inside the Boulders Restricted Zone.
The large rock at the site is marked on the SA Navy charts as "Noah's Ark", and is commonly referred to by local divers as "Ark Rock". The wrecks are associated with the rock by being nearby. There is a wreck of a barge just south of the rock, the wreck of a small steam powered vessel to the west and a larger iron or steel vessel, probably the "Parana" 1862”, to the north west. Another small wreck of a steam powered wooden vessel lies to the south of the barge wreck, near a small group of large rocks, and a third boiler lies near a small group of rocks some distance to the east.
Maximum depth is about 14m on the north side of the main reef and in the area of the main section of the "Parana" wreckage. Most of the area south of Ark Rock is sand bottom at 10 to 11 m depth, and most of the wreckage and rocks extend less than 3m above the bottom.
Visibility is not often very good in this area, but can be 5 to 10m on a good day. It may vary among the listed sites even on the same day.
This is a huge flat topped granite boulder standing on even larger granite outcrop which extends above the sand level. The exposed rock is about 55m long from east to west and 30m from north to south. Mostly sheer sided with small overhangs and some deep crevices. The bottom is sand, sloping very gradually from about 10m at the south of the rock to about 8m near Penguin Point. There are a few pinnacles around the main rock, including one to the west, and at least two to the south.
The small pinnacle about 12m to the west of the main rock rises to quite close to the surface and is topped by kelp. This pinnacle is at S34°11.530’ E018°27.207’ and could be a hazard to boats.
There are assorted cables lying around on the sand in this area which are remnants of the old navy degaussing range. Most of these appear to be south of the barge wreck.
Ark Rock Barge:
This wreck comprises the central section of a steel barge, probably a dredging hopper. The hold is about 3m wide, with buoyancy compartments port and starboard, each about 1.2m wide. The hull is level and projects about 2m above the surface of the sand, Hull plating is gone along the lower sides but the ribs are still there. The hold is of heavier metal and is substantially intact, with heavy beams at deck level spaced about 2m apart. A good wreck for beginners as it is not possible to get lost in it.
Boiler wreck 1:
This wreck is the remains of a small unidentified iron or steel vessel which has mostly rusted away, except for the boiler, what might be the engine crankcase and some of the nearby structure. There may also be more of the hull buried in the sand. Everything is heavily encrusted by crinoids, ascidians and other growth, making identification of the components difficult. The wreckage is about 19m long, 6m wide and 2m high (boiler). The centreline of the vessel lies approximately 030° magnetic.
Boiler wreck 2:
This wreck is the remains of a small steam powered wooden vessel. Most of the hull has gone, but there is a small amount of hull bottom under the power plant. The most notable feature of the wreck is a small boiler, about 1m in diameter and 2m long, standing upright on the remains of the hull. A couple of metres away is what is almost certainly the remains of the steam engine, but it is very heavily encrusted, and not possible to make out the details. The engine lies on it's side. The wreckage is about 12m long and 2 to 3m wide, the top of the boiler stands about 1.5m above the sand. About 20m to the south east on bearing 135° magnetic, is a group of fairly large rocks. The full extent of this group has not been measured, but it is probably not very large.
Boiler wreck 3:
All that is visible of this wreck are two boilers. They are apparently identical, and about 2m diameter and about 5m long, with two fireboxes. Noth are fairly intact, and the casing of boiler 3a has no visible openings through the pressure vessel, while an access opening to the pressure vessel is visible on boiler 3b partway along the left side looking from the firebox end. They appear to be Scotch boilers of fairly ordinary design, and both stand upright on the sand. There is probably more wreckage below the sand supporting the boilers, as if unsupported they would probably have bedded in more deeply. The fireboxes are open, and the outside is moderately encrusted with seaweeds and invertebrates. Boiler 3b is about 30m on bearing 038° magnetic from boiler 3a. Close to the west of boiler 3a is a moderately large granite outcrop, and about 30m to the north east of boiler 3b is a low flattish reef which drops off steeply to the north east.
To the east of Ark Rock is a small iron or steel wreck. The hull is almost complete in outline, with a few gaps. The wreck lies upright on the slightly sloping sand bottom at about 14m depth, with the bow to the north west. The hull is about 4m wide, and probably about 10m long. The remains of the topsides extend a bit over a metre from the sand in most places. No trace of a deck remains, and no trace of an engine can be seen.
A heavily overgrown piece of wreckage about 2m long and 1.5m diameter lies on a fairly extensive and moderately flat rubble bottom at about 9m depth. A hole in one end (probably the north end) allows a view of a perforated plate with possible tubes on the other side. This has the look of some form of heat exchanger, but probably not a boiler.
The wreckage of an iron or steel ship which may be the “Parana”. The wreckage is mostly buried under the sand, with a long strip of hull plating and frames projecting about 0.5 to 1m above the sand. The frame spacing is about 0.5m, and a stringer can also be seen. There are two vertical cylindrical objects about 1.8m diameter and a bit over a metre visible height with small rectangular horizontal openings on the sides, and some door frames and cast iron porthole frames mostly buried in the sand. The main debris field is about 40m long and about 2 to 5m wide at about 120° magnetic. Two other minor debris fields which may be parts of this wreck are known. One is to the north at an unknown position, and the other is to the south at S34°11.497’ E018°27.143’
Concrete pillar arrays
There are two groups of concrete pillars aligned in rows on the sand bottom. There is a double row, originally of 14 pillars in each row, spaced about 2m apart and aligned magnetic north/south, with a gap of about 10m between the rows. This group is centred at S34°11.618' E18°27.277'. The west row now has only 12 pillars, as the southern two have fallen over. They are about 200mm diameter and about 2m high. The east row still has all 14 and they are about 600mm diameter and 3m high.
There is also a single row of pillars, almost identical in size and arrangement to the larger row of the first group, to the west, and centred at S34°11.649' E18°27.220' and aligned magnetic east/west. The extended axis of this group intersects the south end of the first group, at a distance of about 88m These pillars are about 2.5m high.
Geology: Granite of the late Pre-Cambrian Peninsula pluton, surrounded by fine white quartz sand.
Can be dived any time the swell is low and the wind is not too strong. Mostly this will be autumn or winter, as a strong south easter will push up an unpleasant chop. For a shore dive, choose a day when there is not too much wind, as this may set up a surface current.
Parking for shore dives at bottom of Bellevue road at the penguin sanctuary.
Generally considered a boat dive, though all can be dived from shore entry at Penguin Point. There is a swim of about 30 minutes each way, which could be tiring in a chop. The Ark Rock is clearly visible and can not be missed.
This site can also be dived as a coastal underwater orienteering swim. A route from the Pumphouse gulley at Penguin Point via Compass Reef, Photographer's Reef and North Photographer's Reef to Ark Rock, and returning via the Ark Rock Barge wreck, and Boiler wreck 2 to Boulders Beach has been planned and tested. The total point to point distance is about 2km.
Noah’s Ark: There is a band of Black mussels and barnacles around the rock to about 1m below surface, then Red-bait on deeper surfaces. The vertical surfaces and overhangs are heavily encrusted with organisms typical of the area, and include sponges, crinoids, ascidians, sea cucumbers, hydroids and sea fans.
See section on topography of each wreck.
(photographic equipment suggestions)
1. Boat dive: Put down a shot line over the “Parana” wreck. Descend and look at the wreckage, then swim a compass course of 255° magnetic for 58m to a large piece of unidentified wreckage that projects about 2m from the sand at S34°11,497’ E018°11.497’. This debris field is about 12m long at 140° magnetic and may be part of the same ship. From this point swim 100m at 177° magnetic to the Boiler Wreck, then either to Noah’s Ark 70m at 098° magnetic or to the Ark Rock Barge 115m at 184° magnetic. If you wish to continue to Noah’s Ark from the barge, the course is 040° magnetic for about 120m. This route has not been tested. Alternatively, swim 116m on bearing 208° to the Boiler wreck 2
2. Orienteering boat dive: This is a variation on the second long coastal orienteering dive listed below, but is shorter and skips the long swims to and from the shore. The total distance is about 1km, and maximum depth about 15m. (This route has not been tested).
3. Shore dive: Surface swim from entry at the low rock at the north of Penguin Point to the south side of Noah’s Ark (about 550m). Descend and dive round the rock until back at start. Swim a compass course 220° magnetic along the sand bottom about 120m to the Barge wreck. Do a quick tour of wreck and continue toward Penguin Point, crossing over some electrical cables on the way. It may be better to exit at one of the other exit points if conditions require.
4. Long coastal underwater orienteering dive #1 This area has been dived as part of a long orienteering route taking in Compass Reef, Photographer's Reef and North Photographer's Reef. The swim will take somewhat over an hour excluding time spent looking at the scenery and swimming around the landmarks, and depending on your cruising speed. The point to point distance is about 2km.
5. Long coastal underwater orienteering dive #2 Another long compass navigation exercise is to dive all the Ark Rock wrecks and several of the other reefs and features on a single shore dive. This swim is about 1.8km long. Large cylinders will be necessary. (this route has not been tested yet)
No site-specific hazards have been reported
No special skills required. Reasonable fitness is necessary to do this as a shore dive, due to the long swim.
A compass is necessary if you wish to return to shore or navigate between the wrecks under water, and a SMB is desirable to warn boats of your presence during the long swim. A light will help you see into crevices, but is not essential.