Difference between revisions of "Diving the Cape Peninsula and False Bay/Percy's Hole"
Revision as of 14:28, 13 August 2009
The Dive site Percy's Hole is one of the best known and most interesting sites in the Rooi-Els area on the South-East side of False Bay, near Cape Town in the Western Cape province of South Africa. Information is provided which may assist in planning Recreational and Research Scuba diving at this site, and links to photographs of marine organisms that have been found there.
Name "Percy's Hole"
No-one seems to know who Percy is or was, and why this site should be named Percy’s Hole, but it has been known by this name since at least 1983.
S34°17.350’ E018°49.377’ (18km South of Gordon’s Bay)
This is NOT in a Marine Protected Area (2009)
The dives can be done from a boat from Rooi-Els, Gordon’s Bay or Hangklip, but unless you can arrange to launch at Rooi-Els it is a long ride.
For this reason they are mostly done as shore dives, as the shore access is quite good, though quite a long walk and the path is rough, steep in places and may be slippery when wet.
Parking is on the seaward side of the road (R44) on a paved parking bay at S34°17.404’ E018°49.398'. Walk down the path that goes to the right (see map). The middle part of the path is often muddy due to springs, and it becomes rocky lower down.
Entry and exit is in a shallow branch of the gully to the south of the main inlet. This entry point is quite well protected from waves and is accessible when the swell is reasonably low. If inaccessible, visibility will be very poor, and it will not be worth diving. The gully may be safe for entry and exit even if there is a significant amount of white water at the mouth, as the side gullies and kelp dissipate a lot of the power of the waves. (See note under Conditions).
There is also a north entry area with a fairly steep but less muddy climb, which starts at the road sign for a sharp curve slightly north of the parking area. This path leads down to a sloping rock at the south of the little cove at the bend in the road, just north of the seal rock reef.
The dip of the strata is quite steep here, and it can be a little tricky when getting out to avoid slipping on the wet rock. Barnacles help with grip but are unfriendly to dive suits and bare skin. The path is also steep enough to need the use of hands at one point, but there are adequate handholds so this is not a big problem. Conditions will vary depending on tide and swell.
Paved parking bay on seaward side of the road (R44). Sometimes crowded in the Kreef (Rock Lobster) season but usually adequate.
The site is exposed to south west swell. Long period swells will result in poor visibility and a fairly rough entry and exit. The site is usually at it's best during or after south easterly wind in summer, but there are also occasional opportunities in winter when there has been a spell of calm weather with no big storms in the South Atlantic.
This is an area which sometimes has cold water upwellings after the south east wind, and occasionally these upwellings bring clear cold water and excellent diving.
Keep a lookout for times when the swell forecast is short period and low, or is not from the south west.
Winter storms may bring in broken kelp to cover the bottom below the walls, and the visibility is likely to be poor due to suspended organic matter.
A combination of a high tide with moderate south west swell can make conditions tricky for exits at the gully when waves break over the ridge from the south west and cause a rip current to flow out through the gullies and heads which can be difficult to swim in against. In these conditions consider alternative exit points or move in along the bottom, pulling yourself along the rocks and kelp.
Not usually very good. 3 to 5m is fairly common, and occasionally 10m+ has been reported.
The bottom is generally from 14m to 20m, unless you swim way out where 23m is possible on the sand.
Ordovician Sandstones of the Table Mountain group, probably Peninsula formation (uniformly light grey, medium to coarse grained, well bedded quartzitic sandstone Strike roughly north east, dip about 25° south east.
The gully drops down to 14m depth between the heads. There is a stepped wall (2 levels) to the south, and extensive rocky reefs to the north with a swim-through inshore of the exposed rock pinnacles (Seal Rocks). To seaward of these high reefs the bottom slopes down to 23m with sand bottom.
North east side of gully, sharp right
The mouth of the gully drops to 14m, there are some big boulders lying on the bottom and a tall narrow outcrop with kelp on top. The shoreline wall to the north has quite a deep overhang and runs approximately east magnetic until it forms a strait between Seal Rock reef and the shore. It gets shallower until a huge rock almost blocks the way close to where the bigger Seal Rock breaks the surface. Under this is the tunnel (swim-through). It has a nearly level round pebble bottom and vertical access at both ends and in the middle. Beyond the tunnel the strait widens and is partly blocked by some large outcrops and boulders. The Seal Rock reef continues parallel to the shoreline for some way then tapers down. Beyond this, to seaward, the bottom flattens out and becomes a gently sloping pebble/gravel bed, ending at sand, The reef comprises large sandstone outcrops, and has deep overhangs along part of its length. One overhang extends about two metres under the rock with a maximum height of about a metre, and is several metres long.
The shoreline of the north east of the north cove has a small cave. This is at the end of one of the deep gullies that indent the shoreline in this area. The gully bottom is at about 9m, with small to medium rounded boulders on the bottom, then steps up vertically to about 5m at the mouth of the cave. The cave is about 7m wide at the mouth, and the roof is arched and extends to slightly above sea level at most tides. The cave is straight and approximately semi-elliptical in plan, extending roughly 20m into the rock in line with the gully. The floor slopes gently up and the roof down to the back. There are a few large boulders and a lot of small ones on the floor, but the entrance is at all times at least partly visible from the back and would be classed as a cavern. There is a fairly deep horizontal crevice at the base of the north side which is sometimes occupied by large numbers of White seacatfish.
Straight out from gully, and a bit to the right
From the gully mouth straight out there are low rocky outcrops. About 30m out on bearing 030° magnetic is the start of a high broken ridge of rock tending 355° true for 60m with gaps, overhangs etc. Outcrops of moderate and variable height.
This reef appears to be a continuation of the ridge to the north east of the gulley above sea level. The top of the ridge gets slowly deeper further out. The far part of the reef is fairly low, followed by a high pinnacle and dropoff to seaward, and borders on course pebble gravel with occasional small boulders. (This is also the end of the reef described in the previous section).
To the south west of this is a low area with sand and pebble bottom and occasional low rock outcrops that starts quite close inshore, about 45m to seaward of the ridge in front of the entry gully, and extends to magnetic north as far as the edge of the reef. Much of this sandy area is in line with the entry gully, and may well be an underwater extension of the same topographical feature.
The far end of the ridge then tends about 087° magnetic for about 60m and rises from a pebble bottom at about 18m to the top at about 12m. The wall is very sheer in places, with long deep overhangs at the bottom. The shoreward end is shallower and the ridge tapers down to meet the bottom which shelves up more gradually. The seal rock reef is inshore of this area.
South west side of gully, sharp left
The depth is about 12m at the base of the shore wall which is to the left of the gully (south west). The wall is in two sections, The deeper section is from the bottom at about 12m to about 6m, where it shelves shoreward to the ridge which breaks the surface to the south west of the gully mouth. The deeper section of the wall is undercut quite deeply but with not much headroom, and the bottom is sandy near the wall.
Shore access requires a walk down a muddy and slippery path and some scrambling over rocks. Surge may be strong in the gullies and swim-through. At high tide there may be a rip current flowing out through the heads. If you dive during a strong south easterly wind, avoid swimming back on the surface, as the wind will hinder your progress, and could blow you offshore.
There may be broken glass or other garbage on the path. use footwear.
No special skills required. The site is suitable for novice divers and some areas are good snorkelling for those who can go deep enough.
Moderate fitness and agility is required for shore dives.
This is a good site for night dives as they can be done close inshore along the wall, though the climb may be tricky in the dark.
This is a very good site for photography of invertebrates, and a number of sightings of rare organisms have been made here. Visibility is seldom very good, so Macro equipment or an external flash is recommended.
A light is useful for illuminating under overhangs. A compass is convenient for keeping track of where you are. Hard soled booties or some other form of shoe are strongly recommended for the walk to and from the gully. Your footwear will get muddy.
The marine life is varied and abundant, There is a variety of soft corals, colonial ascidians and sponges here that are not easily found on this side of the bay. Fish are not specially plentiful, but a fair variety have been seen. An unusually large variety of nudibranchs may be found if you have a sharp eye, lots of luck and time to search.
Views of the site from the shore.
This view from the road shows the Seal Rocks at Percy’s. The swim-through tunnel is just inshore to the left of these rocks.
View of the gully from the cliff on the north side. The entry point is in the small gully to the left running inshore and parallel to the two ridges. The mouth of the gully at the right side of the photo drops suddenly to 14m. There is a wall on the outside of the ridge in the middle of the photo which is a good site for a night dive.
The path down to the gully is in the middle of this view, taken just below the right hand cross, which has no known connection with the site name. The path is almost always muddy and after rains there may be a small stream running under the bush. The path is slippery and frogs may be seen.
Entry point at the gully at Percy’s at low tide. Swim out to the gap between the rocks in the background and descend to 14m in the centre.
View of Percy’s Hole from the north east showing the north entry area on the far side of the little cove.
The path to the north entry at Percy’s starts here.
The north entry at Rercy’s Hole.
A view towards the North east shoreline showing the little inlets. The cave is just below water level in the second inlet from the right.