Scuba2 Shore Dive October 2007

Scuba2 will be holding their monthly shore dive at North Mole on Sunday, October the 21st. This is a great site for practising your navigation skills trying to find the Gareenup wreck.
Contact Mark Dyson dysonm@iinet.net.au.

Not The Sydney

Sydney Morning Herald reports the Royal Australian Navy has rejected claims the wreck of HMAS Sydney has been found off Dirk Hartog Island. Read more here.

Swan River Wrecks

Only one of the wrecks in the Swan River is protected by either the Maritime Archaeology Act 1973 (Western Australia), or the Historic Shipwrecks Act 1976 (Commonwealth).
The Swan Portland wreck is protected by State legislation. Lost in 1917, she lays 50m upstream of the Goodwood Parade boat ramp.
Latitude 31°57.2260, longitude 115°53.9788.
Read more about Perth historic wrecks here: Historic Shipwrecks of Perth 1656-1942. Search for more wrecks on the Western Australian Maritime Museum Wreckfinder.
Swan River Wreck Dive Sites
Blackwall Reach
The Coombe
Glyde Street
Jerrat Drive

Swan River Marine Life

The Swan River has very little sea grass or weed and the bottom is mainly very fine silt. Though, at first glance, appearing devoid of life, marine animals congregate around wrecks, jetty pylons, and on rocks near the shore.
A range of different sponges, Phylumporifera, live on the wrecks scattered in the river.
Purple tipped sea anemones Pachycerianthus sp. are scatted on the bottom. A number of sea pens, order Pennatulacea, also live in the silt.
During summer you will see a few jellyfish, the most common being moon jelly fish, Aurelia aurita. Also during this time lookout for the jellyfish Phyllorhiza puctata. Look closely to see if any juvenile fish are living among the tentacles.
Several tube worms, family Sabellidae and family Serpulidae, including Protula sp., live on wrecks and jetty pylons.
On the silt you may see the, possibly introduced, tube worm ?Myxicola infundibulum.
Pylons are often covered in barnacles, class Cirripedia.
Western king prawns, Penaeaesus latisulcatus, can be spotted at night, remember bag and size limits apply if you are hunting. Less common in the Swan River is the smaller western school prawn, Metapenaeus dalli. If you are lucky you may find the small, almost transparent, carid shrimp Macrobrachium intermedium near the shore.
Twice I have seen paper bubbles, possibly Bullina lineata. Both times it was amongst the rocks at The Coombe. In the river I have seen one other paper bubble, which may have been Philine angasi, there are records of this species congregating in estuaries.
A number of nudibranchs, family Polyceridae, live in the river, though nowhere near as common as outside the estuary.
Cephalopods I have seen include two unidentified cuttlefish species, family Sepiidae, and one type of squid, possibly southern calamary, Sepioteuthis australis. I have not seen any octopus, family Octopodidae.
A large number of starfish, class Asteroidea, live in the river, possibly the most beautiful is Lucidia australiae with its 'pixellated' body.
The most common crab you will see is the blue manna crab, Portunus pelagicus, again bag and size limits apply. If you look closely at the wrecks you will see a number of other crab species, including decorator crabs.
I have also seen striped cat fish balls, Plotosus lineatus, under a number wrecks. At The Coombe both wrecks and one of the large buoy anchors have resident cobblers, Cnidoglanis macrocephalus, also known as estuary catfish. To be cont...

Other Animals Sharing The Swan
A number of water birds inhabit the river, including, of course, black swans, Cygnus atratus.
I have twice seen darters, Anhinga melanogaster, hunting in the river, once at a depth of 9m.
From the shore, if you are really lucky, you may see one of the rivers resident ospreys, Pandion haliaetus, soaring overhead.

You can read more about the river on this post: Swan River

Swan River

The River
The Swan River is the main waterway in Perth Western Australia. Sixty seven kilometres inland from the river mouth the Swan changes name to the Avon River. The Swan and Avon combined are over 280kms long before emptying into the Indian Ocean.
History
The Whadjuk Noongar people have inhabited the region surrounding the Swan River for over 40,000 years. They believe the river was created by a 'snake like' being called Waugal.
In 1697 VOC Dutch explorer Willem de Vlamingh named the river after the black swan, Cygnus atratus. The first European to sail up the river was the French explorer Nicholas Baudin in 1801. The Swan River Colony, now Perth, was established in 1829.
One of several significant events that have changed the river since the arrival of Europeans, was the widening of the river mouth in 1895. This has led to far greater levels of salt water entering the river.
Future
Check the Swan River Trust Healthy River Program.
Environment & Pollution
Algal blooms are a natural event resulting from high nutrient levels in the river. Nutrients usually enter the river from rural and urban run-off during rainfall. At times the nutrient levels in the river build up and are not 'flushed' as per normal. Blooms are basically high levels of algal growth. Some algae are harmless and some species are toxic. At any time of year the river can have a 'slight' to 'high' green tinge. As algal levels are normally higher after rain, it is recommended you don't swim in the river for 3 days. You can check algal levels here: Swan River Trust Algal Activity Report, and WA Health Department Healthy Swimming.
The Swan, passing through the most populated area in WA, is sometimes affected by toxic spills. You can check warnings and alerts here: Swan River Trust Current Alerts.
Occasionally as you descend, usually during winter, you may notice an 'oily' layer in the water, with almost zero visibility. This is not a bloom or the result of pollution, rather, it is the zone where the cold fresh river water mixes with the warmer salt sea water below.
River Hazards
Algal Blooms have been discussed earlier in this post. As have toxic spills.
The river is a busy place, as you expect in the middle of city with a population of 1.5million. Ferries, motor boats, yachts and kayaks, all moving about day and night. You should always use a dive flag, particularly at night with a strobe attached.
A number of marine species in the river have venomous defence systems, including cobbler, western rock cod and others. Best advice is to always keep you hands to yourself.
Wrecks can be dangerous places. Be careful of sharp rusting edges and broken glass buried in the silt around wrecks.
Always be aware of currents and tides. Some sites can have quite strong currents, particularly Jerrat Drive and Blackwall Reach.
The river can test your navigation skills. Apart from currents, reduced visibility from silting up can find you passing your wreck. Make sure you don't wonder into the main channel.
Swan River Dive Sites
Bicton Baths
Blackwall Reach
The Coombe
Glyde Street
Jerrat Drive
Swan Links
Swan River Marine Life
Swan River Trust
Swan River Trust Algal Activity Report
Swan River Trust Current Alerts
WA Health Department Healthy Swimming
Marine Life Links
Sea Slug Forum
Australian Museum Online site with information on nudibranchs, bubble-shells, sea hares and other sea slugs.

North Mole

Easy shore dive which, may challenge your navigation skills. A good alternative to South Mole.

• Rating Easy dive, challenging navigation.
  
• Depth 9m.
  
• Viz Can vary here, though is never great.
  
• Access Entry to water is extremely difficult, car park next to site.
  

Location
North Mole Drive
East Fremantle, Western Australia
Google Map

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Description
Possibly the Gareenup wreck, a wooden towing lighter, owned by the Swan River Shipping Co, lost on the 21st of August, 1923. She foundered after a collision with the Euro at Victoria Quay. Federal Legislation protects this wreck. Heavy penalties apply for damage, interference or removal of any relics from a registered historic wreck.
Facilities
Parking and public toilet.
The Site

Marine Life

Hazards
Always use a dive flag. Beware of boats. Water entry and exit can be hazardous. Never dive on the harbour side of the mole. Don't stray into the channel. Cobbler, striped catfish and western rock cod all have venomous spines, which can cause painful injuries. Wrecks can have sharp edges.
Links
Historic Shipwrecks Act 1976 (Commonwealth)

Jerrat Drive

A Swan River wreck dive.

• Rating Moderate.
  
• Depth 9m.
  
• Viz 2-5m.
  
• Access Moderate.
  

Location
Jerrat Drive
East Fremantle Western Australia
Google Map

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Description
Two interesting wrecks. One, a WWII landing craft (possibly ALC40), the other, apparently a Chinese junk. The landing craft has many holes, nooks and crannies to peer into, so always take a torch. A nice night dive.
The Site
I am in the process of checking the bearings to both wrecks.
Position
ALC40: latitude 32°01.63848, longitude 115°46.2357
Marine Life
Cuttle fish, western red scorpion cod, Scorpaena sumptuosa, Western Australian seahorse, Hippocampus angustus, stripped cat fish ball, Plotosus lineatus, cobbler, Cnidoglanis macrocephalus, crested morwong, rough leather jacket, pygmy leather jacket, goatfish, flathead, gobbleguts, blowfish, sea pens, tube anemone, sea urchins and sand dollars. Black beam, Acanthopagrus butcheri, often congregate on the barge. For a more detailed description of marine life view this blog: Swan River Marine Life.
Hazards
Always use a dive flag, beware of boat traffic. Cobbler, striped catfish and western rock cod all have venomous spines, which can cause painful injuries. Both wrecks have sharp edges. Strong currents can be deceptive, check tides. Keep off the bottom, the silt is very fine and if stirred up can reduce your visibility. Be aware of Swan River pollution levels. The WA Health Department advises not to swim in the river for 3 days after rain.
Check river pollution levels here:
Swan River Trust Algal Activity Report
Swan River Trust Current Alerts
WA Health Department Healthy Swimming.

Blackwall Reach

Swan River wreck dive. A good alternative site if sea conditions are rough. Bring your camera to snap a few of the many seahorses here.

• Rating Easy to moderate depending on current.
  
• Depth 14m (yacht 16m).
  
• Viz 1-4m, down to 50cm is silt is stirred up. I dived here once, in summer, when the viz was over 10m!
  
• Access Easy water entry. Long, moderate to hard, surface swim.
  

Location
Blackwall Reach Parade
Point Walter Western Australia
Buoy #716 & Buoy #666
Google Maps

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Description
Wreck dive. 3 wrecks close together. Another yacht lies much deeper and further out.
The Site
Park at the northern end of Blackwall Reach Pde. Enter the water near the little jetty and follow the cliff face north for about 180m. Find marker buoy #716, descend buoy line. Two or three metres west of the chain is a large barge (length 21m, beam 7m). The barge rises well off the bottom and is accessible inside.
Off the SW corner is a small dingy, you should see it as you circle the barge if the viz is half decent.
About 8m due north (0°) of the barge is the wreck of a motorboat. The barge and the motorboat are good sites for seahorses, as is the cliff face on the swim back to the beach.
The wreck of an 11m yacht is (approx) 120m further along the cliff face, though I have not seen it. To get there descend buoy #666 and swim for 20m on 200° bearing. The yacht is in 16m of water.
Position
Barge & motorboat: latitude 32°01.154, longitude 115°47.051
Yacht: latitude 32°01.108, longitude 115°47.050
Marine Life
Possibly the best spot in the river to see seahorses.
For a more detailed description of marine life view this blog: Swan River Marine Life.
Hazards
Always use a dive flag. Beware of boat traffic. Don't stray into the channel. Cobbler, striped catfish and western rock cod all have venomous spines, which can cause painful injuries. Both wrecks have sharp edges. Keep off the bottom, the silt is very fine and if stirred can reduce your visibility. On hot days watch for swimmers diving off the cliff face. Be aware of Swan River pollution levels. The WA Health Department advises not to swim in the river for 3 days after rain.
Check river pollution levels here:
Swan River Trust Algal Activity Report
Swan River Trust Current Alerts
WA Health Department Healthy Swimming.

Glyde Street

Swan River shore dive. Easy night dive as there is very little water movement and little navigation required.

• Rating Easy.
  
• Depth 13m.
  
• Viz 2-5m.
  
• Access Easy entry, though a long walk and stairs from any parking.
  

Location
Glyde Street
Mosman Bay, Western Australia.
Google Map

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Description
A motorboat and some tyres form a small artificial reef. Very little navigation required as ropes guide you to the wreck. Surface swim to buoy #435, descend, then follow the rope east to motorboat. The boat used to stand on its end, a very funny sight, now lying on its side. Take care, there is broken glass on the wreck and hidden in the silt.
Marine Life
My last dive here I saw three false Tasmanian blennies, Parablennius intermedius. Find one of the many small holes on the side of the boat, watch and wait. These guys are a very cute fish with a long, fluffy cirri (tentacle) above each eye. For a more detailed description of marine life in the River view: Swan River Marine Life.
Hazards
Always use a dive flag, with a light attached at night. Beware of boat traffic, this site can be very busy at times. Cobbler, striped catfish and western rock cod all have venomous spines, which can cause painful injuries. The wreck has sharp edges. Around the wreck there is broken glass buried in the silt. Keep off the bottom, the silt is very fine and if stirred up can reduce your visibility.
Be aware of Swan River pollution levels. The WA Health Department advises not to swim in the river for 3 days after rain.
Check river pollution levels here:
Swan River Trust Algal Activity Report
Swan River Trust Current Alerts
WA Health Department Healthy Swimming.

The Coombe

Swan River wreck dive.

• Rating Easy, good night dive.
  
• Depth 12m.
  
• Viz 5m-50cm.
  
• Access Enter from The Coombe carpark, beware of rocks in the shallows.
  

Location
The Coombe
Mosman Bay, Western Australia
Google Map

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Description
Two small wrecks, one at 10m, the other at 12m. Good site for night dives. If you gear up just before sunset you may see a pod dolphins move through the dive site. Mid-week you will see lots of club divers and prawn hunters.
Marine Life
For a more detailed description of marine life view this blog: Swan River Marine Life.
Hazards
Always use a dive flag, beware of boat traffic. Cobbler, striped catfish and western rock cod all have venomous spines, which can cause painful injuries. Both wrecks have sharp edges. Around the shallow wreck there is broken glass buried in the silt. Keep off the bottom, the silt is very fine and if stirred up can reduce your visibility to less than 50cm.
Be aware of Swan River pollution levels. The WA Health Department advises not to swim in the river for 3 days after rain.
Check river pollution levels here:
Swan River Trust Algal Activity Report
Swan River Trust Current Alerts
WA Health Department Healthy Swimming.

Rockingham Wreck Trail

A purpose sunk wreck trail. Regularly used by SCUBA schools on weekends.

• Rating Easy.
• Depth 16m.
• Viz 1-6m.
• Access 50m walk, 30m swim, stairs.

Location
Churchill Park
Rockingham Beach Road & Flinders Lane
Rockingham, Western Australia.

Facilities
Bell Park has excellent facilities with BBQ's, toilets, showers, children's play equipment and parking. Across from the park you can grab a coffee from one of the many cafes, a beer from the pub or a tank fill from Bell Scuba.
Description
A collection of small wrecks, two small aircraft and some children's play equipment. This site is extremely busy on Sunday mornings, and can silt up easily, so get there early or try a midweek dive. A good site for a night dive.
The Site

Marine Life

Hazards
Even though there is permanent dive flag at the site I recommend you always use your own dive flag. Watch for boats entering the dive site. Be aware entering wrecks can be dangerous.

HMAS Sydney Found?

The West Australian newspaper reports finding the HMAS Sydney near Dirk Hartog Island. Lying in 150m of water the wreck, possibly the Sydney, was found by a group of amateur historians. Interestingly, though a front page article in print, The West online contains no mention of the discovery.

Read more about the Sydney here:
HMAS Sydney
National Archives
ABC News