Diving the Cape Peninsula and False Bay/MV Aster
The wreck is easily accessible by a short boat trip, and was prepared for diving before it was sunk. The position is well protected from the south easterly wind, and the depth is conveniently suitable for advanced divers. It supports a large variety of marine life, and is structurally still fairly intact.
S34°03.891’ E018°20.955’ (Mast)
In the middle of the mouth of Hout Bay, near the wreck of the Katsu Maru, 700m offshore, and just beyond the main traffic lane.
This site is in a Marine Protected Area (2004). A permit is required.
The 340 ton "MFV Aster" was a South African registered lobster fishing vessel which was prepared as a diver-friendly artificial reef by cleaning and cutting openings into the structure before scuttling. It has been used as a training site for wreck penetration. The Aster was scuttled in Hout Bay near the wreck of the Katzu Maru on 9th August 1997.
Maximum depth is about 28m meters in the scour at the bow and stern at low tide. This may reach 30m at high spring tides. Average depth of the wreck is over 20m. The gunwale of the main deck is at about 24m at low tide, and the top of the mast is at about 9m depth.
Visibility will vary from poor to about as good as you will get in Cape Town. 20m is possible, but 10m is more likely on a fairly good day, and less than 5m is entirely possible. The wreck is on fine sand and the visibility is significantly affected by swell. Large or long period swell will keep particles in suspension near the bottom. There is virtually no silting on the exterior of the wreck, but the interior may be silted in quiet corners.
Flat sand bottom at about 27m. The ship stands almost level imbedded in the bottom as if floating in sand. The bow points towards approximately 330° magnetic (northwest). There is deep scouring of the sand at the bow bow and stern, usually to about 28m maximum at low tide. The vessel is is essentially intact and still looks much like when it was afloat. The hull is intact with a few holes cut in it, and the superstructure is intact except for the wheelhouse, which has lost its forward bulkhead and roof.The tripod mast at the forecastle and the forecastle deck are also intact. There is a fairly large rectangular hatch just forward of the superstructure , leading to a hold, and a winch at each side at the base of the superstructure. The vessel is about 36m long and the beam is about 8m.
The Aster is marked on the charts at the same position as the Katsu Maru, but is about 20m to the northeast of the other wreck, and both can be visited on the same dive.
Geology: Flat quartz sand bottom.
The site is exposed to south westerly swells, which can cause a strong surge. The site is usually at it's best in summer but there are also occasional opportunities in autumn and winter. On rare occasions there may be no surge at all and visibility of over 20m.
This is an area which sometimes has upwellings, caused by strong south easterly winds, resulting in cold clear water, which may develop a plankton bloom over a few days, which will reduce the visibility again.
Keep a lookout for times when the south west swell is low and short period, and there is not too much south easterly wind forecast.
Access is only reasonably practicable by boat. The site is about a 2.2km ride from the harbour slipway. The wreck is in the harbour approaches, and there may be significant boat traffic.
The wreck is heavily encrusted with common feather stars and sponges, with good representation by colonial ascidians and hydroids. The mast has Urchins, black mussels and barnacles near the top. There is a fair range of other species, and the rarely sighted Tasselled nudibranch Kaloplocamus ramosus has been seen here several times. Large rock lobster lurk in the recesses, and rock crabs scuttle around amongst the encrustations of invertebrates. A few small kelp plants have established themselves on shallower parts of the wreck.
Recent wreck in fairly intact condition. The structure is fairly sound and apertures have been cut to make the wreck more diver friendly for penetrations. Most of the structure is clearly recognisable, and all of the exterior is easily accessible for the advanced diver.
Macro and/or wide angle equipment is recommended. Most of the time macro equipment will give the better results, but on a really good day you may get some fine wide angle shots. Macro will require flash.
No special route recommended.
Cold water, occasional fog, and boat traffic. Possible entrapment if the wreck is penetrated. Some of the structure may be unstable, and the superstructure has lost a few components. Strong surge is common if the swell is large or the period long, as the vessel lies directly across the prevailing swell direction and a srong surge will create severe turbulence over the weather side gunwale.
No special skills are required unless penetration is intended. It is necessary to be qualified for 30m dives, so most "Advanced diver" certifications are appropriate.
A light will restore colour and allow you to look into the wreck. A reel and DSMB are worth carrying in case it is necessary to surface away from the shotline. A dry-suit is recommended as the water is usually quite cold, but many divers have dived the Aster in wet suits. Nitrox is recommended to extend no-decompression time.