The American schooners, which sank in 1813, lie 90 metres below the surface of the lake, about 10.5 kilometres off Port Dalhousie. The ships have been owned by the City of Hamilton since 1980, but a partnership with Parks Canada allows surveyors to map out every inch of the boats.
“One of the things you have to do in order to safely do archeological work is to see it on a map,” said Michael McAllister, Hamilton’s coordinator for the survey project.
Using the latest technology, the entire site was mapped out over the course of several years, allowing experts to better determine how risky it would be to take next steps, like recovering artifacts.
“We have no plans, but we need to know the risks to prudently move forward,” McAllister said.
The team also wanted to get detailed images of the wrecks because they're being colonized by a relative of the zebra mussel. A layer of mussels could eventually cover the ships.
The results of the mapping survey were presented last week at the Canadian War Museum in Ottawa by Jonathan Moore, senior underwater archaeologist for Parks Canada. He said the mapping process gave researchers a precise understanding of the positioning, size and details of the ships.
“It was very rewarding work. We were using really advanced technology,” Moore said.
That technology included sonar imaging, which bounces sound waves off the surface of the ships to map out their size and shape.
“Much like an echo-sound or a fish finder,” Moore explained, but more sophisticated and with much higher resolution.
Pushed into service for the U.S. Navy during the War of 1812, the Hamilton and the Scourge were originally merchant ships.
When a sudden squall struck just after midnight on Aug. 8, 1813, the ships went down and have remained at the bottom of Lake Ontario ever since.
When first discovered in the 1970s, the ships were upright, intact and had many of the original instruments still in the same positions they would have been in when the ships sank. All of these elements remain in good condition today according to the latest survey results.
“They were in a remarkably good state of preservation,” Moore said. “They are basically an archeologist’s dream.”
Lake Ontario, as many people know, is cold, dark and murky. Though many of the surveying techniques overcome this by using technology such as sonar to chart the wrecks, Moore explained, careful planning is still necessary to spot the ships in dark water and to capture good images.
“It’s dark because there is no natural light penetrating down that deep, but you can overcome that with artificial light,” he said.
As for the murkiness — caused by stirred-up bits of sediment — technology can help there, too. The team deployed probes that measure water clarity and found that springtime was the best season to view the ships, according to Moore.
The site of the wrecks is designated as one of two underwater National Historic Sites in Ontario.
This means the ships are protected, and diving is prohibited unless an archeological licence is obtained. There is a radar surveillance system in place to monitor the site and to prevent unauthorized divers from trying to sneak a peek.
Amateur maritime enthusiasts will have to settle for the detailed mapping and photography collected by the survey, at least until further exploration, and a possible excavation, can take place. So far, there aren’t any firm plans to bring parts of the ships to the surface, according to Moore. It’s in the hands of the City of Hamilton, he explained.
But, if the city wants to take further steps in exploration, Moore is more than happy to do the job.
“We’re talking with the city all the time,” he said. “It’s been a very, very positive and fruitful collaboration.”