Hammerhead Sharks at Layang Layang

 Ocean diving, Reef diving  1 Response »
Aug 292011
 
Hammerhead Sharks at Layang Layang

About the island As I’ve mentioned before, Layang Layang is a small coral atoll in the South China Sea, northwest off the coast of Malaysian Borneo. With 30 degree water, visibility in excess of 40m and a reef that drops 2000m into the blue depths, the diving is spectacular. One of the key drawcards for Layang Layang is that as an oceanic atoll, it sees a lot of big pelagic fish stopping by. Dogtooth tuna and several kinds of barracuda were common sightings. Trevally would shoot through the reef at high speed, scattering schools of tiny purple reef fish as they hunted. For me, the real attraction was the chance to see schools of scalloped hammerhead sharks. With shark populations [read more…]

Surveying in Mt Hypipamee Crater

 Cave diving  6 Responses »
Aug 222011
 
Surveying in Mt Hypipamee Crater

About the site Mt Hypipamee Crater is located in the Atherton Tablelands in Far North Queensland, 25km from the town of Atherton. The crater is a volcanic vent, created by volcanic gases under pressure exploding out through weak points in the rock 100,000 years ago. Unlike the limestone caves created by the ground water in South Australia, Mt Hypipamee has walls of basalt which appear speckled pink underwater. Our week long expedition had taken several years to come together, requiring permits from the Queensland Department of Environment and Resource Management and permission from the Traditional Owners of the land, the Ngadjon people. A 1959 diving expedition had written up a report of dives to 61m in dark but clear water. The information [read more…]

Cogwheel on the Sir William McPherson

 Ocean diving, Wrecks  No Responses »
Aug 152011
 
Cogwheel on the Sir William McPherson

About the site The Sir William McPherson was a transport ship originally built in 1912, and scuttled in 1949 in an area now known the Ships Graveyard. She lies in about 55m, and this was my first dive on her. There are a large number of wrecks accessible from Portsea, Sorrento and Torquay. Prior to 1935, unwanted or damaged ships were stripped of their valuables and towed to outside the 3 mile Port of Melbourne limit before being sunk. The Great Depression in the 1930s increased the practise as scrap metal prices dropped and it was no longer worth holding onto old hulks. However, after a number of incidents of ships not sinking on target and running aground, Commonwealth legislation [read more…]

Bathtub in Piccaninnie Ponds

 Cave diving, Mt Gambier  No Responses »
Aug 082011
 
Bathtub in Piccaninnie Ponds

About the dive The eagle eyed may have noted an extra diver in the background of the last Piccaninnie Ponds shot I talked about here. The little white speck in the distance is actually a diver heading into the usually-forbidden depths of the cave. The photo was taken on a weekend reserved for research into some of the more unusual aspects of this unique wetlands and cave site. In particular, the team was checking on salinity monitors that had been installed in the cave on a previous project weekend. Piccaninnie Ponds is just over the sand dunes from the ocean, and a reduction in ground water flows following the recent drought may lead to salt water incursion from the ocean [read more…]

Haloclines in Olwolgin Cave

 Cave diving, Roe Plains  7 Responses »
Aug 012011
 
Haloclines in Olwolgin Cave

About the site I’ve already talked about a couple of photos I’ve taken of unique features in the Roe Plains caves, including the Black and White Raft Room and the hanging roots. Cave diving in the Roe Plains provided the biggest photographic challenge I’ve experienced thus far – taking clear pictures in a graduated halocline. Haloclines occur where salty and freshwater meet, creating a mixing layer. Unlike the Mexican caves on the Yucatan Peninsula, the halocline in the Roe Plains caves runs at every level of the water. This means it isn’t possible to swim above it, and any diver movement through the cave mixes water of different levels of salinity. For those who haven’t dived in these conditions before, [read more…]