Point Cloud

The point cloud imagery seen here was collected in 2008 using a dual-axis sonar system mounted on a Remotely Operated Vehicle (ROV) parked on the lake bed.  The sonar was designed and built by ASI Group. The point cloud represents the most accurate scaled mapping of the ships conducted to date. A point cloud is made when a sonar device bounces sound waves off of a ship’s hull and the returning reflections are captured as a series of distinct three dimensional points which are then rendered by computer software into an image. Point cloud images are made by a Remotely Operating Vehicle (ROV) which can withstand the extreme conditions that make it so challenging for human divers at the depths where the ships are located.

The adoption of this safe, non-invasive state of the art approach allows the City of Hamilton and its partners, Parks Canada Underwater Archaeology Service and ASI Group, to continue to collect new information about the vessels. The two ships currently sit upright and mostly intact leaning on their port (left) sides 90 meters below the surface of Lake Ontario. The annual temperature varies by a few degrees Celsius but on average it hovers around 4ºC. In most cases visibility is limited to 10 meters due to particles and tiny animal life suspended in the water. There is a tangle of yards and gaffs, boarding pikes and gun barrels, railings and masts, canister shot and bowsprits on the site. Any of these obstacles can snag safety ropes and air hoses in the deep cold dark. These conditions are very challenging and even when proper safety precautions are taken there is always the chance that mistakes will be made and damage to the vessels, associated artifacts and human remains could occur.