While the magnetometer crew conducted its initial search west of Observatory Cay, a second team embarked upon a metal detector survey of the cay itself and searched for evidence of survivor camps associated with the wrecked vessels Bona Vista and Jenny Lind.
The Australian National Maritime Museum and Silentworld Foundation recently led an expedition to the Australian Coral Sea Territory to conduct an archaeological survey of historic shipwrecks lost at Kenn Reefs during the nineteenth century. The Kenn Reefs expedition is a continuation of an ongoing collaborative project between the museum and Silentworld Foundation that commenced in 2009 and led to the discovery that same year of the wreck of the colonial government schooner Mermaid (lost in 1829 on what is now known as Flora Reef). No less than eight vessels are known to have wrecked at Kenn Reefs between 1828 and 1884, and most grounded in relatively close proximity to one another on the largest of the southernmost reefs in the chain, as it was located within an oft-travelled shipping route, but poorly charted until the mid-nineteenth century.
In the spirit of National Archaeology Week 2016 we took the opportunity to open the floor to you, our audience and community, with the hashtag #AskAnArchaeologist. This was a chance for you to ask your questions about all things archaeology and maritime heritage to our team.
Overnight, the wind from the north-west has abated a little and the swell on the northern exposed edge of Ashmore Reef, where the wreck site is located, has decreased. This allowed us to get dive teams on-site nice and early to take advantage of the calmer seas.
Led by Michael Gooding (Silentworld Foundation), Lee Graham (Australian National Maritime Museum) and Grant Luckman (Department of Environment) the dive teams have continued to plot the scattered remains of the shipwreck by carrying out additional 100 metre-long compass and tape transit surveys from the two main anchor clusters.
Over the last few days the weather conditions on site have started to deteriorate as as the effects of a new monsoonal trough comes into play.
With a substantial surf breaking over the southern and eastern edges of Ferguson Reef and with limited space in the boats we decided to send only single teams of snorkelers onto the reef-top searching for the magnetometer hits that John and Frits had detected on the previous day. Continue reading
Thursday 21 March
Before departing Lizard Island this morning the team took advantage of the early start by climbing Cook’s Look the iconic hill on Lizard Island. The same hill climbed by Lieutenant James Cook and some of the crew of HMB Endeavour in 1770 shortly after that vessel had run aground on a coral patch now known as Endeavour Reef, south of Lizard Island. Cook used this vantage spot to find his way out of the ‘labyrinth’ which had so nearly claimed his vessel.
After climbing Cook’s Look our expedition vessels departed Lizard Island bound for the Flinders Group, 50 or so miles north.
After a smooth passage the two vessels anchored in the channel between the cluster of islands that make up the Flinders Group just south and east of Princess Charlotte Bay. In March 1899 a cyclone destroyed a pearling fleet anchored in the Bay, with the loss of over 400 lives including at least 100 local Aboriginal people who were swept away and drowned as the result of a huge tidal surge associated with the cyclone. Continue reading
Thurs, 19 Jan 2012
People woke up early this morning. They are excited at the prospect of finding another wreck today. The conditions are perfect! The wind had swung to the east and the waves are nearly flat. Our intrepid mag team can’t wait to get out, so a boat is launched off the top deck and Nigel, Lee and Wayne from James Cook University head out at 6 am.
They came back an hour later with reports of a large anomaly in the gutter spotted yesterday. In magnetometer speak it is a multiple di-polar anomaly with a maximum amplitude of 800 gamma lasting at least 6 seconds. In simple English, it means a scattered site of iron debris covering an area of 30-50 metres. Our reference tables for the magnetometer allow us to convert the strength of the anomaly to weight of iron. In 10 metres of water an anomaly of 800 gamma equates to a mass of iron of approximately 10 tonnes!
After breakfast we sent out the two magnetometer teams again. The morning team went back to the west side of the north reef to confirm the earlier find. The other team was working in the lagoon around the coral cay. By mid-morning dive teams were sent into the gutter with metal detectors to try and isolate the source of the anomaly. Three successive dives were unable to locate the source.
At lunchtime we debriefed on the results of our mag and metal detector surveys. Consensus of opinion is that the source of the anomaly is buried beneath the coral sand at such a depth that it is beyond the metal detector’s sensitivity, but is so large that it easily definable on the magnetic signature of the magnetometer. As we are not allowed to disturb the bottom sediments by any excavation, we are unable to confirm the source iron.
From the historical records we know that the Lion had a 316 lb iron anchor, two iron try-pots weighing a total of 676 lbs., 500 iron harpoons and lances which would weigh over 1 tonne, and 6 tonnes of hoop iron to bind the whale oil barrels. We also assume that the Lion was armed with at least one cannon, as the accounts for the fit-out of the voyage lists two casks of cannon powder. We also know that on its previous voyage Captain Hardwick used canon to ward off an attack by South Sea Islanders. This would seem to correlate very closely to the observed anomaly.
All divers were up by 4 pm. We moved everyone onto the coral cay for the annual team photo. Unfortunately, with the two second time delay Xanthe wasn’t able to get into her own photo!
Sunday, 8 Jan 2012
After a 6 am breakfast, we started preparing the magnetometer for an early start to take advantage of the morning high tide. We left for the inside of the reef and set up the equipment in the Caribe, the larger inflatable boat. After about a half hour a rogue wave broke over the side of the boat and splashed the power inverter and computer. The inverter failed immediately. We dried the equipment, switched the inverter to our spare, and continued using the magnetometer. Half an hour later the same thing happened again. We cancelled the survey and headed back to Kanimbla.
I flushed the inverters with fresh water to remove the corrosive salts from the sea water. Then we let them dry in the sun. As a final measure we flushed the circuit board with rubbing alcohol to remove any remaining dampness. I left them while the crew had lunch and when I hooked them up again, one came back to life, but the other was well and truly fried!
In the afternoon, our team started testing the back-up magnetometer we shipped out from Western Australia. It kept blowing fuses and we found there was a wiring fault in the power box. The team decided to start a manta board survey along the north side of the coral cay at about 3 pm. We were in the water for about an hour and a half before returning to Kanimbla.
We downloaded the GPS tracks of our survey and annotated our field notes, finally finishing off at 6 pm. Here are a few photos of what the other teams got up to during the day….
Lee Graham and his team found a lead scupper that would have drained water off the deck.
A broken blade stem glass. Very high quality, possibly lead crystal. The fact that it is still clear indicates that it hasn’t been exposed to the coral and surf for very long.
Paul Hundley (Sr. Curator and archaeologist)
Saturday, 7 Jan 2012
After breakfast we started preparing the magnetometer for its check-out, an important piece of equipment that surveys magnetic fields to help us detect archaeological artefacts. With the equipment set up in the Caribe, the larger inflatable boat, we left for the inside of the reef. But after about an hour we lost power to the computer operating the mag! We went back to the Kanimbla to trouble-shoot the power inverter.
After lunch and our afternoon briefing we prepared for our next dive. Our team was assigned to do a drift snorkel dive from inside the reef break north to the lagoon. We loaded our snorkel gear into one of the inflatables and headed for the reef. Only half an hour into our dive, Jacqui Mullen spotted a pintle, rudder fitting.
About 10 metres away Maddie spotted a matching gudgeon. A real find as they are indicative of the size of the vessel they were attached to. We continued our dive and about 15 metres further on I found a pulley sheave with its bronze coak still in place.
At the end of the dive, we were in deeper water and spotted an unidentifiable conglomeration of iron and timber. That will be something to look more closely at later. We got into the boat and headed back to Kanimbla. We were met with great excitement over our finds. We took some of the other divers back out to show them the material and finally got back to Kanimbla at 4.30 pm.
We downloaded the GPS tracks of our dives and the locations of the finds. It has been another very big day with significant finds in a number of areas. Stay tuned…. This is turning out to be a fast-paced project with new discoveries every day.
Below are a few more photos of what else has been happening.
Paul Hundley (Sr. Curator and archaeologist)