Range testing in ideal conditions
This was carried out off the east coast of New Zealand in calm seas with a sandy sloping bottom in the lee of an island. The diver was held in position directly below the tender and the monitoring boat was moved away from the diver position and range tested acoustically with verification via radar. In these ideal conditions the Diver DACAD System™ achieved a consistent range of 1.25 miles (2,000m) although distances greater than this were recorded.
Range testing in marina conditions
These tests were performed in a large marina north of Auckland in New Zealand. There were a lot of boat movements in the marina and the test was undertaken at a water depth of approximately 10 feet (3m). Water conditions included a small amount of silt (1 foot – 300mm) over a hard sand stone. The boat was positioned at the end of one marina and a diver swam up that marina and was tracked down the length of the marina (i.e. the diver was tracked perpendicular to the boats). In a further test the monitoring boat was moved to one end of the marina and the diver swam up another marina (11 marinas away) and was able to be tracked through more than 20 sets of boat keels. Tracking of more than 0.5 miles (800m) was achieved in this cluttered environment.
Testing in Owl Creek, Virginia, USA
Set up for this test was on a wharf with the divers swimming around 100 yards away. The Dunking Transducer was lowered into approximately 1 foot (300mm) of water and the divers swam from a dive tender into the middle of Owl Creek. The divers were in water up to 30 feet deep (10m), the sea floor was silt/sand and the weather calm and hot. Given that this was a very challenging environment, with a narrow acoustic approach path to the Dunking Transducer in only 1 foot (300mm) of water, the tracking was very reliable.
Testing in Singapore
This test was in very challenging water with vertical and horizontal thermoclines. The particular stretch of water is known as the “acoustic killer”. Tracking was positioned at the wharf with divers entering the water around 0.5 miles (850m) away and at a depth of 45 feet (15m). The water was very contaminated with high debris and oil slicks. As soon as the divers hit the water they were tracked.